Merge pull request #8203 from NixOS/backport-8201-to-2.15-maintenance

[Backport 2.15-maintenance] Do not gate or hide experimental settings

.github/ISSUE_TEMPLATE/missing_documentation.md

@@ -11,10 +11,6 @@ assignees: ''
 
 <!-- describe your problem -->
 
-## Proposal
-
-<!-- propose a solution -->
-
 ## Checklist
 
 <!-- make sure this issue is not redundant or obsolete -->
@@ -26,6 +22,10 @@ assignees: ''
 [source]: https://github.com/NixOS/nix/tree/master/doc/manual/src
 [open documentation issues and pull requests]: https://github.com/NixOS/nix/labels/documentation
 
+## Proposal
+
+<!-- propose a solution -->
+
 ## Priorities
 
 Add :+1: to [issues you find important](https://github.com/NixOS/nix/issues?q=is%3Aissue+is%3Aopen+sort%3Areactions-%2B1-desc).

.github/PULL_REQUEST_TEMPLATE.md

@@ -10,6 +10,24 @@
 
 <!-- Large change: Provide instructions to reviewers how to read the diff. -->
 
+# Checklist for maintainers
+
+<!-- Contributors: please leave this as is -->
+
+Maintainers: tick if completed or explain if not relevant
+
+ - [ ] agreed on idea
+ - [ ] agreed on implementation strategy
+ - [ ] tests, as appropriate
+   - functional tests - `tests/**.sh`
+   - unit tests - `src/*/tests`
+   - integration tests - `tests/nixos/*`
+ - [ ] documentation in the manual
+ - [ ] documentation in the internal API docs
+ - [ ] code and comments are self-explanatory
+ - [ ] commit message explains why the change was made
+ - [ ] new feature or incompatible change: updated release notes
+
 # Priorities
 
 Add :+1: to [pull requests you find important](https://github.com/NixOS/nix/pulls?q=is%3Aopen+sort%3Areactions-%2B1-desc).

.github/labeler.yml

@@ -16,8 +16,8 @@
 "new-cli":
   - src/nix/**/*
 
-"with-tests":
+"tests":
   # Unit tests
   - src/*/tests/**/*
   # Functional and integration tests
-  - tests/functional/**/*
+  - tests/**/*

.github/workflows/backport.yml

@@ -14,14 +14,14 @@ jobs:
     if: github.repository_owner == 'NixOS' && github.event.pull_request.merged == true && (github.event_name != 'labeled' || startsWith('backport', github.event.label.name))
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           # required to find all branches
           fetch-depth: 0
       - name: Create backport PRs
         # should be kept in sync with `version`
-        uses: zeebe-io/backport-action@v1.4.0
+        uses: zeebe-io/backport-action@v1.2.0
         with:
           # Config README: https://github.com/zeebe-io/backport-action#backport-action
           github_token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/ci.yml

@@ -11,19 +11,15 @@ jobs:
   tests:
     needs: [check_secrets]
     strategy:
-      fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     timeout-minutes: 60
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v3
       with:
         fetch-depth: 0
-    - uses: cachix/install-nix-action@v23
-      with:
-        # The sandbox would otherwise be disabled by default on Darwin
-        extra_nix_config: "sandbox = true"
+    - uses: cachix/install-nix-action@v20
     - run: echo CACHIX_NAME="$(echo $GITHUB_REPOSITORY-install-tests | tr "[A-Z]/" "[a-z]-")" >> $GITHUB_ENV
     - uses: cachix/cachix-action@v12
       if: needs.check_secrets.outputs.cachix == 'true'
@@ -58,11 +54,11 @@ jobs:
     outputs:
       installerURL: ${{ steps.prepare-installer.outputs.installerURL }}
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v3
       with:
         fetch-depth: 0
     - run: echo CACHIX_NAME="$(echo $GITHUB_REPOSITORY-install-tests | tr "[A-Z]/" "[a-z]-")" >> $GITHUB_ENV
-    - uses: cachix/install-nix-action@v23
+    - uses: cachix/install-nix-action@v20
       with:
         install_url: https://releases.nixos.org/nix/nix-2.13.3/install
     - uses: cachix/cachix-action@v12
@@ -77,14 +73,13 @@ jobs:
     needs: [installer, check_secrets]
     if: github.event_name == 'push' && needs.check_secrets.outputs.cachix == 'true'
     strategy:
-      fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v3
     - run: echo CACHIX_NAME="$(echo $GITHUB_REPOSITORY-install-tests | tr "[A-Z]/" "[a-z]-")" >> $GITHUB_ENV
-    - uses: cachix/install-nix-action@v23
+    - uses: cachix/install-nix-action@v20
       with:
         install_url: '${{needs.installer.outputs.installerURL}}'
         install_options: "--tarball-url-prefix https://${{ env.CACHIX_NAME }}.cachix.org/serve"
@@ -108,10 +103,10 @@ jobs:
       needs.check_secrets.outputs.docker == 'true'
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v3
       with:
         fetch-depth: 0
-    - uses: cachix/install-nix-action@v23
+    - uses: cachix/install-nix-action@v20
       with:
         install_url: https://releases.nixos.org/nix/nix-2.13.3/install
     - run: echo CACHIX_NAME="$(echo $GITHUB_REPOSITORY-install-tests | tr "[A-Z]/" "[a-z]-")" >> $GITHUB_ENV
@@ -127,7 +122,7 @@ jobs:
     - run: docker tag nix:$NIX_VERSION nixos/nix:$NIX_VERSION
     - run: docker tag nix:$NIX_VERSION nixos/nix:master
     - name: Login to Docker Hub
-      uses: docker/login-action@v3
+      uses: docker/login-action@v2
       with:
         username: ${{ secrets.DOCKERHUB_USERNAME }}
         password: ${{ secrets.DOCKERHUB_TOKEN }}

.github/workflows/hydra_status.yml

@@ -13,7 +13,7 @@ jobs:
     if: github.repository_owner == 'NixOS'
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v3
       with:
         fetch-depth: 0
     - run: bash scripts/check-hydra-status.sh

.github/workflows/labels.yml

@@ -21,4 +21,4 @@ jobs:
     - uses: actions/labeler@v4
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
-        sync-labels: false
+        sync-labels: true

.gitignore

@@ -18,7 +18,7 @@ perl/Makefile.config
 /doc/manual/generated/*
 /doc/manual/nix.json
 /doc/manual/conf-file.json
-/doc/manual/language.json
+/doc/manual/builtins.json
 /doc/manual/xp-features.json
 /doc/manual/src/SUMMARY.md
 /doc/manual/src/command-ref/new-cli
@@ -26,7 +26,6 @@ perl/Makefile.config
 /doc/manual/src/command-ref/experimental-features-shortlist.md
 /doc/manual/src/contributing/experimental-feature-descriptions.md
 /doc/manual/src/language/builtins.md
-/doc/manual/src/language/builtin-constants.md
 
 # /scripts/
 /scripts/nix-profile.sh
@@ -41,19 +40,17 @@ perl/Makefile.config
 /src/libexpr/parser-tab.hh
 /src/libexpr/parser-tab.output
 /src/libexpr/nix.tbl
-/tests/unit/libexpr/libnixexpr-tests
+/src/libexpr/tests/libnixexpr-tests
 
 # /src/libstore/
 *.gen.*
-/tests/unit/libstore/libnixstore-tests
+/src/libstore/tests/libnixstore-tests
 
 # /src/libutil/
-/tests/unit/libutil/libnixutil-tests
+/src/libutil/tests/libnixutil-tests
 
 /src/nix/nix
 
-/src/nix/doc
-
 # /src/nix-env/
 /src/nix-env/nix-env
 
@@ -79,24 +76,21 @@ perl/Makefile.config
 
 /src/build-remote/build-remote
 
-# /tests/functional/
-/tests/functional/test-tmp
-/tests/functional/common/vars-and-functions.sh
-/tests/functional/result*
-/tests/functional/restricted-innocent
-/tests/functional/shell
-/tests/functional/shell.drv
-/tests/functional/config.nix
-/tests/functional/ca/config.nix
-/tests/functional/dyn-drv/config.nix
-/tests/functional/repl-result-out
-/tests/functional/test-libstoreconsumer/test-libstoreconsumer
+# /tests/
+/tests/test-tmp
+/tests/common/vars-and-functions.sh
+/tests/result*
+/tests/restricted-innocent
+/tests/shell
+/tests/shell.drv
+/tests/config.nix
+/tests/ca/config.nix
+/tests/repl-result-out
 
-# /tests/functional/lang/
-/tests/functional/lang/*.out
-/tests/functional/lang/*.out.xml
-/tests/functional/lang/*.err
-/tests/functional/lang/*.ast
+# /tests/lang/
+/tests/lang/*.out
+/tests/lang/*.out.xml
+/tests/lang/*.ast
 
 /perl/lib/Nix/Config.pm
 /perl/lib/Nix/Store.cc
@@ -139,6 +133,3 @@ nix-rust/target
 result
 
 .vscode/
-
-# clangd and possibly more
-.cache/

.version

@@ -1 +1 @@
-2.18.4
+2.15.0

CONTRIBUTING.md

@@ -5,6 +5,7 @@ We appreciate your support.
 
 Reading and following these guidelines will help us make the contribution process easy and effective for everyone involved.
 
+
 ## Report a bug
 
 1. Check on the [GitHub issue tracker](https://github.com/NixOS/nix/issues) if your bug was already reported.
@@ -30,9 +31,6 @@ Check out the [security policy](https://github.com/NixOS/nix/security/policy).
 
 2. Search for related issues that cover what you're going to work on. It could help to mention there that you will work on the issue.
 
-   Issues labeled [good first issue](https://github.com/NixOS/nix/labels/good-first-issue) should be relatively easy to fix and are likely to get merged quickly.
-   Pull requests addressing issues labeled [idea approved](https://github.com/NixOS/nix/labels/idea%20approved) are especially welcomed by maintainers and will receive prioritised review.
-
 3. Check the [Nix reference manual](https://nixos.org/manual/nix/unstable/contributing/hacking.html) for information on building Nix and running its tests.
 
    For contributions to the command line interface, please check the [CLI guidelines](https://nixos.org/manual/nix/unstable/contributing/cli-guideline.html).
@@ -40,27 +38,14 @@ Check out the [security policy](https://github.com/NixOS/nix/security/policy).
 4. Make your changes!
 
 5. [Create a pull request](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/creating-a-pull-request) for your changes.
-   * Link related issues in your pull request to inform interested parties and future contributors about your change.
-   * Make sure to have [a clean history of commits on your branch by using rebase](https://www.digitalocean.com/community/tutorials/how-to-rebase-and-update-a-pull-request).
-     If your pull request closes one or multiple issues, note that in the description using `Closes: #<number>`, as it will then happen automatically when your change is merged.
    * [Mark the pull request as draft](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/changing-the-stage-of-a-pull-request) if you're not done with the changes.
+   * Make sure to have [a clean history of commits on your branch by using rebase](https://www.digitalocean.com/community/tutorials/how-to-rebase-and-update-a-pull-request).
+   * Link related issues in your pull request to inform interested parties and future contributors about your change.
+     If your pull request closes one or multiple issues, note that in the description using `Closes: #<number>`, as it will then happen automatically when your change is merged.
 
 6. Do not expect your pull request to be reviewed immediately.
    Nix maintainers follow a [structured process for reviews and design decisions](https://github.com/NixOS/nix/tree/master/maintainers#project-board-protocol), which may or may not prioritise your work.
 
-   Following this checklist will make the process smoother for everyone:
-
-   - [ ] Fixes an [idea approved](https://github.com/NixOS/nix/labels/idea%20approved) issue
-   - [ ] Tests, as appropriate:
-     - Functional tests – [`tests/functional/**.sh`](./tests/functional)
-     - Unit tests – [`src/*/tests`](./src/)
-     - Integration tests – [`tests/nixos/*`](./tests/nixos)
-   - [ ] User documentation in the [manual](..doc/manual/src)
-   - [ ] API documentation in header files
-   - [ ] Code and comments are self-explanatory
-   - [ ] Commit message explains **why** the change was made
-   - [ ] New feature or incompatible change: updated [release notes](./doc/manual/src/release-notes/rl-next.md)
-
 7. If you need additional feedback or help to getting pull request into shape, ask other contributors using [@mentions](https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#mentioning-people-and-teams).
 
 ## Making changes to the Nix manual

Makefile

@@ -23,17 +23,11 @@ makefiles = \
 
 ifeq ($(tests), yes)
 makefiles += \
-  tests/unit/libutil/local.mk \
-  tests/unit/libutil-support/local.mk \
-  tests/unit/libstore/local.mk \
-  tests/unit/libstore-support/local.mk \
-  tests/unit/libexpr/local.mk \
-  tests/unit/libexpr-support/local.mk \
-  tests/functional/local.mk \
-  tests/functional/ca/local.mk \
-  tests/functional/dyn-drv/local.mk \
-  tests/functional/test-libstoreconsumer/local.mk \
-  tests/functional/plugins/local.mk
+  src/libutil/tests/local.mk \
+  src/libstore/tests/local.mk \
+  src/libexpr/tests/local.mk \
+  tests/local.mk \
+  tests/plugins/local.mk
 else
 makefiles += \
   mk/disable-tests.mk

configure.ac

@@ -5,14 +5,7 @@ AC_CONFIG_AUX_DIR(config)
 
 AC_PROG_SED
 
-# Construct a Nix system name (like "i686-linux"):
-# https://www.gnu.org/software/autoconf/manual/html_node/Canonicalizing.html#index-AC_005fCANONICAL_005fHOST-1
-# The inital value is produced by the `config/config.guess` script:
-# upstream: https://git.savannah.gnu.org/cgit/config.git/tree/config.guess
-# It has the following form, which is not documented anywhere:
-# <cpu>-<vendor>-<os>[<version>][-<abi>]
-# If `./configure` is passed any of the `--host`, `--build`, `--target` options, the value comes from `config/config.sub` instead:
-# upstream: https://git.savannah.gnu.org/cgit/config.git/tree/config.sub
+# Construct a Nix system name (like "i686-linux").
 AC_CANONICAL_HOST
 AC_MSG_CHECKING([for the canonical Nix system name])
 
@@ -191,7 +184,7 @@ fi
 
 # Look for OpenSSL, a required dependency. FIXME: this is only (maybe)
 # used by S3BinaryCacheStore.
-PKG_CHECK_MODULES([OPENSSL], [libcrypto >= 1.1.1], [CXXFLAGS="$OPENSSL_CFLAGS $CXXFLAGS"])
+PKG_CHECK_MODULES([OPENSSL], [libcrypto], [CXXFLAGS="$OPENSSL_CFLAGS $CXXFLAGS"])
 
 
 # Look for libarchive.
@@ -252,17 +245,6 @@ case "$host_os" in
                         [CXXFLAGS="$LIBSECCOMP_CFLAGS $CXXFLAGS"])
       have_seccomp=1
       AC_DEFINE([HAVE_SECCOMP], [1], [Whether seccomp is available and should be used for sandboxing.])
-      AC_COMPILE_IFELSE([
-        AC_LANG_SOURCE([[
-          #include <seccomp.h>
-          #ifndef __SNR_fchmodat2
-          # error "Missing support for fchmodat2"
-          #endif
-        ]])
-      ], [], [
-        echo "libseccomp is missing __SNR_fchmodat2. Please provide libseccomp 2.5.5 or later"
-        exit 1
-      ])
     else
       have_seccomp=
     fi

doc/internal-api/doxygen.cfg.in

@@ -39,21 +39,17 @@ INPUT                  = \
   src/libcmd \
   src/libexpr \
   src/libexpr/flake \
-  tests/unit/libexpr \
-  tests/unit/libexpr/value \
-  tests/unit/libexpr/test \
-  tests/unit/libexpr/test/value \
+  src/libexpr/tests \
+  src/libexpr/tests/value \
   src/libexpr/value \
   src/libfetchers \
   src/libmain \
   src/libstore \
   src/libstore/build \
   src/libstore/builtins \
-  tests/unit/libstore \
-  tests/unit/libstore/test \
+  src/libstore/tests \
   src/libutil \
-  tests/unit/libutil \
-  tests/unit/libutil/test \
+  src/libutil/tests \
   src/nix \
   src/nix-env \
   src/nix-store

doc/manual/custom.css

@@ -1,25 +1,3 @@
-:root {
-    --sidebar-width: 23em;
-}
-
-h1.menu-title::before {
-  content: "";
-  background-image: url("./favicon.svg");
-  padding: 1.25em;
-  background-position: center center;
-  background-size: 2em;
-  background-repeat: no-repeat;
-}
-
-
-h1.menu-title {
-  padding: 0.5em;
-}
-
-.sidebar .sidebar-scrollbox {
-  padding: 1em;
-}
-
 h1:not(:first-of-type) {
     margin-top: 1.3em;
 }

doc/manual/generate-builtin-constants.nix

@@ -1,31 +0,0 @@
-let
-  inherit (builtins) concatStringsSep attrValues mapAttrs;
-  inherit (import ./utils.nix) optionalString squash;
-in
-
-builtinsInfo:
-let
-  showBuiltin = name: { doc, type, impure-only }:
-    let
-      type' = optionalString (type != null) " (${type})";
-
-      impureNotice = optionalString impure-only ''
-        > **Note**
-        >
-        > Not available in [pure evaluation mode](@docroot@/command-ref/conf-file.md#conf-pure-eval).
-      '';
-    in
-    squash ''
-      <dt id="builtins-${name}">
-        <a href="#builtins-${name}"><code>${name}</code></a>${type'}
-      </dt>
-      <dd>
-
-      ${doc}
-
-      ${impureNotice}
-
-      </dd>
-    '';
-in
-concatStringsSep "\n" (attrValues (mapAttrs showBuiltin builtinsInfo))

doc/manual/generate-builtins.nix

@@ -1,28 +1,20 @@
+builtinsDump:
 let
-  inherit (builtins) concatStringsSep attrValues mapAttrs;
-  inherit (import ./utils.nix) optionalString squash;
-in
-
-builtinsInfo:
-let
-  showBuiltin = name: { doc, args, arity, experimental-feature }:
+  showBuiltin = name:
     let
-      experimentalNotice = optionalString (experimental-feature != null) ''
-        This function is only available if the [${experimental-feature}](@docroot@/contributing/experimental-features.md#xp-feature-${experimental-feature}) experimental feature is enabled.
-      '';
+      inherit (builtinsDump.${name}) doc args;
     in
-    squash ''
+    ''
       <dt id="builtins-${name}">
         <a href="#builtins-${name}"><code>${name} ${listArgs args}</code></a>
       </dt>
       <dd>
 
-      ${doc}
-
-      ${experimentalNotice}
+        ${doc}
 
       </dd>
     '';
-  listArgs = args: concatStringsSep " " (map (s: "<var>${s}</var>") args);
+  listArgs = args: builtins.concatStringsSep " " (map (s: "<var>${s}</var>") args);
 in
-concatStringsSep "\n" (attrValues (mapAttrs showBuiltin builtinsInfo))
+with builtins; concatStringsSep "\n" (map showBuiltin (attrNames builtinsDump))
+

doc/manual/generate-manpage.nix

@@ -1,24 +1,16 @@
-let
-  inherit (builtins)
-    attrNames attrValues fromJSON listToAttrs mapAttrs
-    concatStringsSep concatMap length lessThan replaceStrings sort;
-  inherit (import ./utils.nix) concatStrings optionalString filterAttrs trim squash unique showSettings;
-in
+cliDumpStr:
 
-inlineHTML: commandDump:
+with builtins;
+with import ./utils.nix;
 
 let
 
-  commandInfo = fromJSON commandDump;
-
   showCommand = { command, details, filename, toplevel }:
     let
 
       result = ''
         > **Warning** \
-        > This program is
-        > [**experimental**](@docroot@/contributing/experimental-features.md#xp-feature-nix-command)
-        > and its interface is subject to change.
+        > This program is **experimental** and its interface is subject to change.
 
         # Name
 
@@ -30,25 +22,26 @@ let
 
         ${maybeSubcommands}
 
-        ${maybeStoreDocs}
+        ${maybeDocumentation}
 
         ${maybeOptions}
       '';
 
       showSynopsis = command: args:
         let
-          showArgument = arg: "*${arg.label}*" + optionalString (! arg ? arity) "...";
+          showArgument = arg: "*${arg.label}*" + (if arg ? arity then "" else "...");
           arguments = concatStringsSep " " (map showArgument args);
         in ''
          `${command}` [*option*...] ${arguments}
         '';
 
-      maybeSubcommands = optionalString (details ? commands && details.commands != {})
-         ''
+      maybeSubcommands = if details ? commands && details.commands != {}
+        then ''
            where *subcommand* is one of the following:
 
            ${subcommands}
-         '';
+         ''
+        else "";
 
       subcommands = if length categories > 1
         then listCategories
@@ -70,11 +63,12 @@ let
         * [`${command} ${name}`](./${appendName filename name}.md) - ${subcmd.description}
       '';
 
-      maybeStoreDocs = optionalString
-        (details ? doc)
-        (replaceStrings ["@stores@"] [storeDocs] details.doc);
+      maybeDocumentation =
+        if details ? doc
+        then replaceStrings ["@stores@"] [storeDocs] details.doc
+        else "";
 
-      maybeOptions = optionalString (details.flags != {}) ''
+      maybeOptions = if details.flags == {} then "" else ''
         # Options
 
         ${showOptions details.flags toplevel.flags}
@@ -84,28 +78,21 @@ let
         let
           allOptions = options // commonOptions;
           showCategory = cat: ''
-            ${optionalString (cat != "") "**${cat}:**"}
+            ${if cat != "" then "**${cat}:**" else ""}
 
             ${listOptions (filterAttrs (n: v: v.category == cat) allOptions)}
             '';
           listOptions = opts: concatStringsSep "\n" (attrValues (mapAttrs showOption opts));
           showOption = name: option:
             let
-              result = trim ''
-                - ${item}
-                  ${option.description}
-              '';
-              item = if inlineHTML
-                then ''<span id="opt-${name}">[`--${name}`](#opt-${name})</span> ${shortName} ${labels}''
-                else "`--${name}` ${shortName} ${labels}";
-              shortName = optionalString
-                (option ? shortName)
-                ("/ `-${option.shortName}`");
-              labels = optionalString
-                (option ? labels)
-                (concatStringsSep " " (map (s: "*${s}*") option.labels));
-            in result;
-          categories = sort lessThan (unique (map (cmd: cmd.category) (attrValues allOptions)));
+              shortName = if option ? shortName then "/ `-${option.shortName}`" else "";
+              labels = if option ? labels then (concatStringsSep " " (map (s: "*${s}*") option.labels)) else "";
+            in trim ''
+              - `--${name}` ${shortName} ${labels}
+
+                ${option.description}
+            '';
+          categories = sort builtins.lessThan (unique (map (cmd: cmd.category) (attrValues allOptions)));
         in concatStrings (map showCategory categories);
     in squash result;
 
@@ -126,11 +113,13 @@ let
       };
     in [ cmd ] ++ concatMap subcommand (attrNames details.commands or {});
 
+  cliDump = builtins.fromJSON cliDumpStr;
+
   manpages = processCommand {
     command = "nix";
-    details = commandInfo.args;
+    details = cliDump.args;
     filename = "nix";
-    toplevel = commandInfo.args;
+    toplevel = cliDump.args;
   };
 
   tableOfContents = let
@@ -140,33 +129,16 @@ let
 
   storeDocs =
     let
-      showStore = name: { settings, doc, experimentalFeature }:
-        let
-          experimentalFeatureNote = optionalString (experimentalFeature != null) ''
-            > **Warning**
-            > This store is part of an
-            > [experimental feature](@docroot@/contributing/experimental-features.md).
-
-            To use this store, you need to make sure the corresponding experimental feature,
-            [`${experimentalFeature}`](@docroot@/contributing/experimental-features.md#xp-feature-${experimentalFeature}),
-            is enabled.
-            For example, include the following in [`nix.conf`](#):
-
-            ```
-            extra-experimental-features = ${experimentalFeature}
-            ```
-          '';
-        in ''
+      showStore = name: { settings, doc }:
+        ''
           ## ${name}
 
           ${doc}
 
-          ${experimentalFeatureNote}
-
           **Settings**:
 
-          ${showSettings { inherit inlineHTML; } settings}
+          ${showSettings { useAnchors = false; } settings}
         '';
-    in concatStrings (attrValues (mapAttrs showStore commandInfo.stores));
+    in concatStrings (attrValues (mapAttrs showStore cliDump.stores));
 
 in (listToAttrs manpages) // { "SUMMARY.md" = tableOfContents; }

doc/manual/local.mk

@@ -11,7 +11,6 @@ man-pages := $(foreach n, \
 	nix-prefetch-url.1 nix-channel.1 \
 	nix-hash.1 nix-copy-closure.1 \
 	nix.conf.5 nix-daemon.8 \
-	nix-profiles.5 \
 , $(d)/$(n))
 
 # man pages for subcommands
@@ -86,24 +85,18 @@ $(d)/nix.conf.5: $(d)/src/command-ref/conf-file.md
 	$(trace-gen) lowdown -sT man --nroff-nolinks -M section=5 $^.tmp -o $@
 	@rm $^.tmp
 
-$(d)/nix-profiles.5: $(d)/src/command-ref/files/profiles.md
-	@printf "Title: %s\n\n" "$$(basename $@ .5)" > $^.tmp
-	@cat $^ >> $^.tmp
-	$(trace-gen) lowdown -sT man --nroff-nolinks -M section=5 $^.tmp -o $@
-	@rm $^.tmp
-
 $(d)/src/SUMMARY.md: $(d)/src/SUMMARY.md.in $(d)/src/command-ref/new-cli $(d)/src/contributing/experimental-feature-descriptions.md
 	@cp $< $@
 	@$(call process-includes,$@,$@)
 
 $(d)/src/command-ref/new-cli: $(d)/nix.json $(d)/utils.nix $(d)/generate-manpage.nix $(bindir)/nix
 	@rm -rf $@ $@.tmp
-	$(trace-gen) $(nix-eval) --write-to $@.tmp --expr 'import doc/manual/generate-manpage.nix true (builtins.readFile $<)'
+	$(trace-gen) $(nix-eval) --write-to $@.tmp --expr 'import doc/manual/generate-manpage.nix (builtins.readFile $<)'
 	@mv $@.tmp $@
 
 $(d)/src/command-ref/conf-file.md: $(d)/conf-file.json $(d)/utils.nix $(d)/src/command-ref/conf-file-prefix.md $(d)/src/command-ref/experimental-features-shortlist.md $(bindir)/nix
 	@cat doc/manual/src/command-ref/conf-file-prefix.md > $@.tmp
-	$(trace-gen) $(nix-eval) --expr '(import doc/manual/utils.nix).showSettings { inlineHTML = true; } (builtins.fromJSON (builtins.readFile $<))' >> $@.tmp;
+	$(trace-gen) $(nix-eval) --expr '(import doc/manual/utils.nix).showSettings { useAnchors = true; } (builtins.fromJSON (builtins.readFile $<))' >> $@.tmp;
 	@mv $@.tmp $@
 
 $(d)/nix.json: $(bindir)/nix
@@ -128,20 +121,14 @@ $(d)/xp-features.json: $(bindir)/nix
 	$(trace-gen) $(dummy-env) NIX_PATH=nix/corepkgs=corepkgs $(bindir)/nix __dump-xp-features > $@.tmp
 	@mv $@.tmp $@
 
-$(d)/src/language/builtins.md: $(d)/language.json $(d)/generate-builtins.nix $(d)/src/language/builtins-prefix.md $(bindir)/nix
+$(d)/src/language/builtins.md: $(d)/builtins.json $(d)/generate-builtins.nix $(d)/src/language/builtins-prefix.md $(bindir)/nix
 	@cat doc/manual/src/language/builtins-prefix.md > $@.tmp
-	$(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-builtins.nix (builtins.fromJSON (builtins.readFile $<)).builtins' >> $@.tmp;
+	$(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-builtins.nix (builtins.fromJSON (builtins.readFile $<))' >> $@.tmp;
 	@cat doc/manual/src/language/builtins-suffix.md >> $@.tmp
 	@mv $@.tmp $@
 
-$(d)/src/language/builtin-constants.md: $(d)/language.json $(d)/generate-builtin-constants.nix $(d)/src/language/builtin-constants-prefix.md $(bindir)/nix
-	@cat doc/manual/src/language/builtin-constants-prefix.md > $@.tmp
-	$(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-builtin-constants.nix (builtins.fromJSON (builtins.readFile $<)).constants' >> $@.tmp;
-	@cat doc/manual/src/language/builtin-constants-suffix.md >> $@.tmp
-	@mv $@.tmp $@
-
-$(d)/language.json: $(bindir)/nix
-	$(trace-gen) $(dummy-env) NIX_PATH=nix/corepkgs=corepkgs $(bindir)/nix __dump-language > $@.tmp
+$(d)/builtins.json: $(bindir)/nix
+	$(trace-gen) $(dummy-env) NIX_PATH=nix/corepkgs=corepkgs $(bindir)/nix __dump-builtins > $@.tmp
 	@mv $@.tmp $@
 
 # Generate the HTML manual.
@@ -173,7 +160,7 @@ doc/manual/generated/man1/nix3-manpages: $(d)/src/command-ref/new-cli
 	done
 	@touch $@
 
-$(docdir)/manual/index.html: $(MANUAL_SRCS) $(d)/book.toml $(d)/anchors.jq $(d)/custom.css $(d)/src/SUMMARY.md $(d)/src/command-ref/new-cli $(d)/src/contributing/experimental-feature-descriptions.md $(d)/src/command-ref/conf-file.md $(d)/src/language/builtins.md $(d)/src/language/builtin-constants.md $(d)/src/favicon.png $(d)/src/favicon.svg
+$(docdir)/manual/index.html: $(MANUAL_SRCS) $(d)/book.toml $(d)/anchors.jq $(d)/custom.css $(d)/src/SUMMARY.md $(d)/src/command-ref/new-cli $(d)/src/contributing/experimental-feature-descriptions.md $(d)/src/command-ref/conf-file.md $(d)/src/language/builtins.md
 	$(trace-gen) \
 		tmp="$$(mktemp -d)"; \
 		cp -r doc/manual "$$tmp"; \

doc/manual/redirects.js

@@ -1,9 +1,7 @@
-// redirect rules for URL fragments (client-side) to prevent link rot.
-// this must be done on the client side, as web servers do not see the fragment part of the URL.
-// it will only work with JavaScript enabled in the browser, but this is the best we can do here.
-// see ./_redirects for path redirects (client-side)
+// redirect rules for anchors ensure backwards compatibility of URLs.
+// this must be done on the client side, as web servers do not see the anchor part of the URL.
 
-// redirects are declared as follows:
+// redirections are declared as follows:
 // each entry has as its key a path matching the requested URL path, relative to the mdBook document root.
 //
 //     IMPORTANT: it must specify the full path with file name and suffix
@@ -21,7 +19,6 @@ const redirects = {
     "chap-distributed-builds": "advanced-topics/distributed-builds.html",
     "chap-post-build-hook": "advanced-topics/post-build-hook.html",
     "chap-post-build-hook-caveats": "advanced-topics/post-build-hook.html#implementation-caveats",
-    "chap-writing-nix-expressions": "language/index.html",
     "part-command-ref": "command-ref/command-ref.html",
     "conf-allow-import-from-derivation": "command-ref/conf-file.html#conf-allow-import-from-derivation",
     "conf-allow-new-privileges": "command-ref/conf-file.html#conf-allow-new-privileges",
@@ -284,7 +281,7 @@ const redirects = {
     "chap-introduction": "introduction.html",
     "ch-basic-package-mgmt": "package-management/basic-package-mgmt.html",
     "ssec-binary-cache-substituter": "package-management/binary-cache-substituter.html",
-    "sec-channels": "command-ref/nix-channel.html",
+    "sec-channels": "package-management/channels.html",
     "ssec-copy-closure": "package-management/copy-closure.html",
     "sec-garbage-collection": "package-management/garbage-collection.html",
     "ssec-gc-roots": "package-management/garbage-collector-roots.html",
@@ -333,31 +330,14 @@ const redirects = {
     "ssec-relnotes-2.0": "release-notes/rl-2.0.html",
     "ssec-relnotes-2.1": "release-notes/rl-2.1.html",
     "ssec-relnotes-2.2": "release-notes/rl-2.2.html",
-    "ssec-relnotes-2.3": "release-notes/rl-2.3.html",
+    "ssec-relnotes-2.3": "release-notes/rl-2.3.html"
   },
   "language/values.html": {
     "simple-values": "#primitives",
     "lists": "#list",
     "strings": "#string",
     "lists": "#list",
-    "attribute-sets": "#attribute-set",
-  },
-  "installation/installing-binary.html": {
-    "linux": "uninstall.html#linux",
-    "macos": "uninstall.html#macos",
-    "uninstalling": "uninstall.html",
-  }
-  "contributing/hacking.html": {
-    "nix-with-flakes": "#building-nix-with-flakes",
-    "classic-nix": "#building-nix",
-    "running-tests": "testing.html#running-tests",
-    "unit-tests": "testing.html#unit-tests",
-    "functional-tests": "testing.html#functional-tests",
-    "debugging-failing-functional-tests": "testing.html#debugging-failing-functional-tests",
-    "integration-tests": "testing.html#integration-tests",
-    "installer-tests": "testing.html#installer-tests",
-    "one-time-setup": "testing.html#one-time-setup",
-    "using-the-ci-generated-installer-for-manual-testing": "testing.html#using-the-ci-generated-installer-for-manual-testing",
+    "attribute-sets": "#attribute-set"
   }
 };
 

doc/manual/rl-next/harden-user-sandboxing.md

@@ -1,8 +0,0 @@
----
-synopsis: Harden the user sandboxing
-significance: significant
-issues:
-prs: <only provided once merged>
----
-
-The build directory has been hardened against interference with the outside world by nesting it inside another directory owned by (and only readable by) the daemon user.

doc/manual/rl-next/leading-period.md

@@ -1,10 +0,0 @@
----
-synopsis: Store paths are allowed to start with `.`
-issues: 912
-prs: 9867 9091 9095 9120 9121 9122 9130 9219 9224
----
-
-Leading periods were allowed by accident in Nix 2.4. The Nix team has considered this to be a bug, but this behavior has since been relied on by users, leading to unnecessary difficulties.
-From now on, leading periods are officially, definitively supported. The names `.` and `..` are disallowed, as well as those starting with `.-` or `..-`.
-
-Nix versions that denied leading periods are documented [in the issue](https://github.com/NixOS/nix/issues/912#issuecomment-1919583286).

doc/manual/src/SUMMARY.md.in

@@ -15,12 +15,12 @@
     - [Multi-User Mode](installation/multi-user.md)
   - [Environment Variables](installation/env-variables.md)
   - [Upgrading Nix](installation/upgrading.md)
-  - [Uninstalling Nix](installation/uninstall.md)
 - [Package Management](package-management/package-management.md)
   - [Basic Package Management](package-management/basic-package-mgmt.md)
   - [Profiles](package-management/profiles.md)
   - [Garbage Collection](package-management/garbage-collection.md)
     - [Garbage Collector Roots](package-management/garbage-collector-roots.md)
+  - [Channels](package-management/channels.md)
   - [Sharing Packages Between Machines](package-management/sharing-packages.md)
     - [Serving a Nix store via HTTP](package-management/binary-cache-substituter.md)
     - [Copying Closures via SSH](package-management/copy-closure.md)
@@ -91,27 +91,13 @@
 {{#include ./command-ref/new-cli/SUMMARY.md}}
   - [Files](command-ref/files.md)
     - [nix.conf](command-ref/conf-file.md)
-    - [Profiles](command-ref/files/profiles.md)
-      - [manifest.nix](command-ref/files/manifest.nix.md)
-      - [manifest.json](command-ref/files/manifest.json.md)
-    - [Channels](command-ref/files/channels.md)
-    - [Default Nix expression](command-ref/files/default-nix-expression.md)
-- [Architecture and Design](architecture/architecture.md)
-  - [File System Object](architecture/file-system-object.md)
-- [Protocols](protocols/protocols.md)
-  - [Serving Tarball Flakes](protocols/tarball-fetcher.md)
-  - [Derivation "ATerm" file format](protocols/derivation-aterm.md)
+- [Architecture](architecture/architecture.md)
 - [Glossary](glossary.md)
 - [Contributing](contributing/contributing.md)
   - [Hacking](contributing/hacking.md)
-  - [Testing](contributing/testing.md)
   - [Experimental Features](contributing/experimental-features.md)
   - [CLI guideline](contributing/cli-guideline.md)
-  - [C++ style guide](contributing/cxx.md)
 - [Release Notes](release-notes/release-notes.md)
-  - [Release 2.18 (2023-09-20)](release-notes/rl-2.18.md)
-  - [Release 2.17 (2023-07-24)](release-notes/rl-2.17.md)
-  - [Release 2.16 (2023-05-31)](release-notes/rl-2.16.md)
   - [Release 2.15 (2023-04-11)](release-notes/rl-2.15.md)
   - [Release 2.14 (2023-02-28)](release-notes/rl-2.14.md)
   - [Release 2.13 (2023-01-17)](release-notes/rl-2.13.md)

doc/manual/src/_redirects

@@ -1,30 +0,0 @@
-# redirect rules for paths (server-side) to prevent link rot.
-# see ./redirects.js for redirects based on URL fragments (client-side)
-#
-# concrete user story this supports:
-# - user finds URL to the manual for Nix x.y
-# - Nix x.z (z > y) is the most recent release
-# - updating the version in the URL will show the right thing
-#
-# format documentation:
-# - https://docs.netlify.com/routing/redirects/#syntax-for-the-redirects-file
-# - https://docs.netlify.com/routing/redirects/redirect-options/
-#
-# conventions:
-# - always force (<CODE>!) since this allows re-using file names
-# - group related paths to ease readability
-# - always append new redirects to the end of the file
-# - redirects that should have been there but are missing can be inserted where they belong
-
-/expressions/expression-language /language/ 301!
-/expressions/language-values /language/values 301!
-/expressions/language-constructs /language/constructs 301!
-/expressions/language-operators /language/operators 301!
-/expressions/* /language/:splat 301!
-
-/package-management/basic-package-mgmt /command-ref/nix-env 301!
-
-/package-management/channels* /command-ref/nix-channel 301!
-
-/package-management/s3-substituter* /command-ref/new-cli/nix3-help-stores#s3-binary-cache-store 301!
-

doc/manual/src/advanced-topics/advanced-topics.md

@@ -1 +1 @@
-This section lists advanced topics related to builds and builds performance
+

doc/manual/src/advanced-topics/diff-hook.md

@@ -48,13 +48,13 @@ If the build passes and is deterministic, Nix will exit with a status
 code of 0:
 
 ```console
-$ nix-build ./deterministic.nix --attr stable
+$ nix-build ./deterministic.nix -A stable
 this derivation will be built:
   /nix/store/z98fasz2jqy9gs0xbvdj939p27jwda38-stable.drv
 building '/nix/store/z98fasz2jqy9gs0xbvdj939p27jwda38-stable.drv'...
 /nix/store/yyxlzw3vqaas7wfp04g0b1xg51f2czgq-stable
 
-$ nix-build ./deterministic.nix --attr stable --check
+$ nix-build ./deterministic.nix -A stable --check
 checking outputs of '/nix/store/z98fasz2jqy9gs0xbvdj939p27jwda38-stable.drv'...
 /nix/store/yyxlzw3vqaas7wfp04g0b1xg51f2czgq-stable
 ```
@@ -63,13 +63,13 @@ If the build is not deterministic, Nix will exit with a status code of
 1:
 
 ```console
-$ nix-build ./deterministic.nix --attr unstable
+$ nix-build ./deterministic.nix -A unstable
 this derivation will be built:
   /nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv
 building '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv'...
 /nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable
 
-$ nix-build ./deterministic.nix --attr unstable --check
+$ nix-build ./deterministic.nix -A unstable --check
 checking outputs of '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv'...
 error: derivation '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv' may
 not be deterministic: output '/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable' differs
@@ -89,7 +89,7 @@ Using `--check` with `--keep-failed` will cause Nix to keep the second
 build's output in a special, `.check` path:
 
 ```console
-$ nix-build ./deterministic.nix --attr unstable --check --keep-failed
+$ nix-build ./deterministic.nix -A unstable --check --keep-failed
 checking outputs of '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv'...
 note: keeping build directory '/tmp/nix-build-unstable.drv-0'
 error: derivation '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv' may

doc/manual/src/advanced-topics/distributed-builds.md

@@ -38,9 +38,11 @@ contains Nix.
 
 > **Warning**
 >
-> If you are building via the Nix daemon, it is the Nix daemon user account (that is, `root`) that should have SSH access to a user (not necessarily `root`) on the remote machine.
->
-> If you can’t or don’t want to configure `root` to be able to access the remote machine, you can use a private Nix store instead by passing e.g. `--store ~/my-nix` when running a Nix command from the local machine.
+> If you are building via the Nix daemon, it is the Nix daemon user
+> account (that is, `root`) that should have SSH access to the remote
+> machine. If you can’t or don’t want to configure `root` to be able to
+> access to remote machine, you can use a private Nix store instead by
+> passing e.g. `--store ~/my-nix`.
 
 The list of remote machines can be specified on the command line or in
 the Nix configuration file. The former is convenient for testing. For

doc/manual/src/advanced-topics/post-build-hook.md

@@ -90,7 +90,7 @@ Then, restart the `nix-daemon`.
 Build any derivation, for example:
 
 ```console
-$ nix-build --expr '(import <nixpkgs> {}).writeText "example" (builtins.toString builtins.currentTime)'
+$ nix-build -E '(import <nixpkgs> {}).writeText "example" (builtins.toString builtins.currentTime)'
 this derivation will be built:
   /nix/store/s4pnfbkalzy5qz57qs6yybna8wylkig6-example.drv
 building '/nix/store/s4pnfbkalzy5qz57qs6yybna8wylkig6-example.drv'...

doc/manual/src/architecture/architecture.md

@@ -7,11 +7,11 @@ It should help users understand why Nix behaves as it does, and it should help d
 
 Nix consists of [hierarchical layers].
 
-[hierarchical layers]: https://en.wikipedia.org/wiki/Multitier_architecture#Layers
+[hierarchical layers]: https://en.m.wikipedia.org/wiki/Multitier_architecture#Layers
 
 The following [concept map] shows its main components (rectangles), the objects they operate on (rounded rectangles), and their interactions (connecting phrases):
 
-[concept map]: https://en.wikipedia.org/wiki/Concept_map
+[concept map]: https://en.m.wikipedia.org/wiki/Concept_map
 
 ```
 
@@ -76,7 +76,7 @@ The result of a build task can be input to another build task.
 The following [data flow diagram] shows a build plan for illustration.
 Build inputs used as instructions to a build task are marked accordingly:
 
-[data flow diagram]: https://en.wikipedia.org/wiki/Data-flow_diagram
+[data flow diagram]: https://en.m.wikipedia.org/wiki/Data-flow_diagram
 
 ```
 +--------------------------------------------------------------------+

doc/manual/src/architecture/file-system-object.md

@@ -1,64 +0,0 @@
-# File System Object
-
-Nix uses a simplified model of the file system, which consists of file system objects.
-Every file system object is one of the following:
-
- - File
-
-   - A possibly empty sequence of bytes for contents
-   - A single boolean representing the [executable](https://en.m.wikipedia.org/wiki/File-system_permissions#Permissions) permission
-
- - Directory
-
-   Mapping of names to child file system objects
-
- - [Symbolic link](https://en.m.wikipedia.org/wiki/Symbolic_link)
-
-   An arbitrary string.
-   Nix does not assign any semantics to symbolic links.
-
-File system objects and their children form a tree.
-A bare file or symlink can be a root file system object.
-
-Nix does not encode any other file system notions such as [hard links](https://en.m.wikipedia.org/wiki/Hard_link), [permissions](https://en.m.wikipedia.org/wiki/File-system_permissions), timestamps, or other metadata.
-
-## Examples of file system objects
-
-A plain file:
-
-```
-50 B, executable: false
-```
-
-An executable file:
-
-```
-122 KB, executable: true
-```
-
-A symlink:
-
-```
--> /usr/bin/sh
-```
-
-A directory with contents:
-
-```
-├── bin
-│   └── hello: 35 KB, executable: true
-└── share
-    ├── info
-    │   └── hello.info: 36 KB, executable: false
-    └── man
-        └── man1
-            └── hello.1.gz: 790 B, executable: false
-```
-
-A directory that contains a symlink and other directories:
-
-```
-├── bin -> share/go/bin
-├── nix-support/
-└── share/
-```

doc/manual/src/command-ref/conf-file-prefix.md

@@ -4,67 +4,49 @@
 
 # Description
 
-Nix supports a variety of configuration settings, which are read from configuration files or taken as command line flags.
+By default Nix reads settings from the following places:
 
-## Configuration file
+  - The system-wide configuration file `sysconfdir/nix/nix.conf` (i.e.
+    `/etc/nix/nix.conf` on most systems), or `$NIX_CONF_DIR/nix.conf` if
+    `NIX_CONF_DIR` is set. Values loaded in this file are not forwarded
+    to the Nix daemon. The client assumes that the daemon has already
+    loaded them.
 
-By default Nix reads settings from the following places, in that order:
+  - If `NIX_USER_CONF_FILES` is set, then each path separated by `:`
+    will be loaded in reverse order.
 
-1. The system-wide configuration file `sysconfdir/nix/nix.conf` (i.e. `/etc/nix/nix.conf` on most systems), or `$NIX_CONF_DIR/nix.conf` if [`NIX_CONF_DIR`](./env-common.md#env-NIX_CONF_DIR) is set.
+    Otherwise it will look for `nix/nix.conf` files in `XDG_CONFIG_DIRS`
+    and `XDG_CONFIG_HOME`. If unset, `XDG_CONFIG_DIRS` defaults to
+    `/etc/xdg`, and `XDG_CONFIG_HOME` defaults to `$HOME/.config`
+    as per [XDG Base Directory Specification](https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html).
 
-   Values loaded in this file are not forwarded to the Nix daemon.
-   The client assumes that the daemon has already loaded them.
+  - If `NIX_CONFIG` is set, its contents is treated as the contents of
+    a configuration file.
 
-1. If [`NIX_USER_CONF_FILES`](./env-common.md#env-NIX_USER_CONF_FILES) is set, then each path separated by `:` will be loaded in reverse order.
+The configuration files consist of `name = value` pairs, one per
+line. Other files can be included with a line like `include path`,
+where *path* is interpreted relative to the current conf file and a
+missing file is an error unless `!include` is used instead. Comments
+start with a `#` character. Here is an example configuration file:
 
-   Otherwise it will look for `nix/nix.conf` files in `XDG_CONFIG_DIRS` and [`XDG_CONFIG_HOME`](./env-common.md#env-XDG_CONFIG_HOME).
-   If unset, `XDG_CONFIG_DIRS` defaults to `/etc/xdg`, and `XDG_CONFIG_HOME` defaults to `$HOME/.config` as per [XDG Base Directory Specification](https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html).
+    keep-outputs = true       # Nice for developers
+    keep-derivations = true   # Idem
 
-1. If [`NIX_CONFIG`](./env-common.md#env-NIX_CONFIG) is set, its contents are treated as the contents of a configuration file.
+You can override settings on the command line using the `--option`
+flag, e.g. `--option keep-outputs false`. Every configuration setting
+also has a corresponding command line flag, e.g. `--max-jobs 16`; for
+Boolean settings, there are two flags to enable or disable the setting
+(e.g. `--keep-failed` and `--no-keep-failed`).
 
-### File format
+A configuration setting usually overrides any previous value. However,
+you can prefix the name of the setting by `extra-` to *append* to the
+previous value. For instance,
 
-Configuration files consist of `name = value` pairs, one per line.
-Comments start with a `#` character.
+    substituters = a b
+    extra-substituters = c d
 
-Example:
+defines the `substituters` setting to be `a b c d`. This is also
+available as a command line flag (e.g. `--extra-substituters`).
 
-```
-keep-outputs = true       # Nice for developers
-keep-derivations = true   # Idem
-```
-
-Other files can be included with a line like `include <path>`, where `<path>` is interpreted relative to the current configuration file.
-A missing file is an error unless `!include` is used instead.
-
-A configuration setting usually overrides any previous value.
-However, for settings that take a list of items, you can prefix the name of the setting by `extra-` to *append* to the previous value.
-
-For instance,
-
-```
-substituters = a b
-extra-substituters = c d
-```
-
-defines the `substituters` setting to be `a b c d`.
-
-Unknown option names are not an error, and are simply ignored with a warning.
-
-## Command line flags
-
-Configuration options can be set on the command line, overriding the values set in the [configuration file](#configuration-file):
-
-- Every configuration setting has corresponding command line flag (e.g. `--max-jobs 16`).
-  Boolean settings do not need an argument, and can be explicitly disabled with the `no-` prefix (e.g. `--keep-failed` and `--no-keep-failed`).
-
-  Unknown option names are invalid flags (unless there is already a flag with that name), and are rejected with an error.
-
-- The flag `--option <name> <value>` is interpreted exactly like a `<name> = <value>` in a setting file.
-
-  Unknown option names are ignored with a warning.
-
-The `extra-` prefix is supported for settings that take a list of items (e.g. `--extra-trusted users alice` or `--option extra-trusted-users alice`).
-
-# Available settings
+The following settings are currently available:
 

doc/manual/src/command-ref/env-common.md

@@ -71,12 +71,9 @@ Most Nix commands interpret the following environment variables:
     Settings are separated by the newline character.
 
   - <span id="env-NIX_USER_CONF_FILES">[`NIX_USER_CONF_FILES`](#env-NIX_USER_CONF_FILES)</span>\
-    Overrides the location of the Nix user configuration files to load from.
-
-    The default are the locations according to the [XDG Base Directory Specification].
-    See the [XDG Base Directories](#xdg-base-directories) sub-section for details.
-
-    The variable is treated as a list separated by the `:` token.
+    Overrides the location of the user Nix configuration files to load
+    from (defaults to the XDG spec locations). The variable is treated
+    as a list separated by the `:` token.
 
   - <span id="env-TMPDIR">[`TMPDIR`](#env-TMPDIR)</span>\
     Use the specified directory to store temporary files. In particular,
@@ -106,19 +103,15 @@ Most Nix commands interpret the following environment variables:
     384 MiB. Setting it to a low value reduces memory consumption, but
     will increase runtime due to the overhead of garbage collection.
 
-## XDG Base Directories
+## XDG Base Directory
 
-Nix follows the [XDG Base Directory Specification].
-
-For backwards compatibility, Nix commands will follow the standard only when [`use-xdg-base-directories`] is enabled.
-[New Nix commands](@docroot@/command-ref/new-cli/nix.md) (experimental) conform to the standard by default.
-
-The following environment variables are used to determine locations of various state and configuration files:
+New Nix commands conform to the [XDG Base Directory Specification], and use the following environment variables to determine locations of various state and configuration files:
 
 - [`XDG_CONFIG_HOME`]{#env-XDG_CONFIG_HOME} (default `~/.config`)
 - [`XDG_STATE_HOME`]{#env-XDG_STATE_HOME} (default `~/.local/state`)
 - [`XDG_CACHE_HOME`]{#env-XDG_CACHE_HOME} (default `~/.cache`)
 
+Classic Nix commands can also be made to follow this standard using the [`use-xdg-base-directories`] configuration option.
 
 [XDG Base Directory Specification]: https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
-[`use-xdg-base-directories`]: @docroot@/command-ref/conf-file.md#conf-use-xdg-base-directories
+[`use-xdg-base-directories`]: @docroot@/command-ref/conf-file.md#conf-use-xdg-base-directories

doc/manual/src/command-ref/experimental-commands.md

@@ -1,6 +1,6 @@
 # Experimental Commands
 
-This section lists [experimental commands](@docroot@/contributing/experimental-features.md#xp-feature-nix-command).
+This section lists experimental commands.
 
 > **Warning**
 >

doc/manual/src/command-ref/files/channels.md

@@ -1,26 +0,0 @@
-## Channels
-
-A directory containing symlinks to Nix channels, managed by [`nix-channel`]:
-
-- `$XDG_STATE_HOME/nix/profiles/channels` for regular users
-- `$NIX_STATE_DIR/profiles/per-user/root/channels` for `root`
-
-[`nix-channel`] uses a [profile](@docroot@/command-ref/files/profiles.md) to store channels.
-This profile contains symlinks to the contents of those channels.
-
-## Subscribed channels
-
-The list of subscribed channels is stored in
-
-- `~/.nix-channels`
-- `$XDG_STATE_HOME/nix/channels` if [`use-xdg-base-directories`] is set to `true`
-
-in the following format:
-
-```
-<url> <name>
-...
-```
-
-[`nix-channel`]: @docroot@/command-ref/nix-channel.md
-[`use-xdg-base-directories`]: @docroot@/command-ref/conf-file.md#conf-use-xdg-base-directories

doc/manual/src/command-ref/files/default-nix-expression.md

@@ -1,52 +0,0 @@
-## Default Nix expression
-
-The source for the default [Nix expressions](@docroot@/language/index.md) used by [`nix-env`]:
-
-- `~/.nix-defexpr`
-- `$XDG_STATE_HOME/nix/defexpr` if [`use-xdg-base-directories`] is set to `true`.
-
-It is loaded as follows:
-
-- If the default expression is a file, it is loaded as a Nix expression.
-- If the default expression is a directory containing a `default.nix` file, that `default.nix` file is loaded as a Nix expression.
-- If the default expression is a directory without a `default.nix` file, then its contents (both files and subdirectories) are loaded as Nix expressions.
-  The expressions are combined into a single attribute set, each expression under an attribute with the same name as the original file or subdirectory.
-  Subdirectories without a `default.nix` file are traversed recursively in search of more Nix expressions, but the names of these intermediate directories are not added to the attribute paths of the default Nix expression.
-
-Then, the resulting expression is interpreted like this:
-
-- If the expression is an attribute set, it is used as the default Nix expression.
-- If the expression is a function, an empty set is passed as argument and the return value is used as the default Nix expression.
-
-
-For example, if the default expression contains two files, `foo.nix` and `bar.nix`, then the default Nix expression will be equivalent to
-
-```nix
-{
-  foo = import ~/.nix-defexpr/foo.nix;
-  bar = import ~/.nix-defexpr/bar.nix;
-}
-```
-
-The file [`manifest.nix`](@docroot@/command-ref/files/manifest.nix.md) is always ignored.
-
-The command [`nix-channel`] places a symlink to the user's current [channels profile](@docroot@/command-ref/files/channels.md) in this directory.
-This makes all subscribed channels available as attributes in the default expression.
-
-## User channel link
-
-A symlink that ensures that [`nix-env`] can find your channels:
-
-- `~/.nix-defexpr/channels`
-- `$XDG_STATE_HOME/defexpr/channels` if [`use-xdg-base-directories`] is set to `true`.
-
-This symlink points to:
-
-- `$XDG_STATE_HOME/profiles/channels` for regular users
-- `$NIX_STATE_DIR/profiles/per-user/root/channels` for `root`
-
-In a multi-user installation, you may also have `~/.nix-defexpr/channels_root`, which links to the channels of the root user.[`nix-env`]: ../nix-env.md
-
-[`nix-env`]: @docroot@/command-ref/nix-env.md
-[`nix-channel`]: @docroot@/command-ref/nix-channel.md
-[`use-xdg-base-directories`]: @docroot@/command-ref/conf-file.md#conf-use-xdg-base-directories

doc/manual/src/command-ref/files/manifest.json.md

@@ -1,45 +0,0 @@
-## `manifest.json`
-
-The manifest file records the provenance of the packages that are installed in a [profile](./profiles.md) managed by [`nix profile`](@docroot@/command-ref/new-cli/nix3-profile.md) (experimental).
-
-Here is an example of what the file might look like after installing `zoom-us` from Nixpkgs:
-
-```json
-{
-  "version": 1,
-  "elements": [
-    {
-      "active": true,
-      "attrPath": "legacyPackages.x86_64-linux.zoom-us",
-      "originalUrl": "flake:nixpkgs",
-      "storePaths": [
-        "/nix/store/wbhg2ga8f3h87s9h5k0slxk0m81m4cxl-zoom-us-5.3.469451.0927"
-      ],
-      "uri": "github:NixOS/nixpkgs/13d0c311e3ae923a00f734b43fd1d35b47d8943a"
-    },
-    …
-  ]
-}
-```
-
-Each object in the array `elements` denotes an installed package and
-has the following fields:
-
-* `originalUrl`: The [flake reference](@docroot@/command-ref/new-cli/nix3-flake.md) specified by
-  the user at the time of installation (e.g. `nixpkgs`). This is also
-  the flake reference that will be used by `nix profile upgrade`.
-
-* `uri`: The locked flake reference to which `originalUrl` resolved.
-
-* `attrPath`: The flake output attribute that provided this
-  package. Note that this is not necessarily the attribute that the
-  user specified, but the one resulting from applying the default
-  attribute paths and prefixes; for instance, `hello` might resolve to
-  `packages.x86_64-linux.hello` and the empty string to
-  `packages.x86_64-linux.default`.
-
-* `storePath`: The paths in the Nix store containing the package.
-
-* `active`: Whether the profile contains symlinks to the files of this
-  package. If set to false, the package is kept in the Nix store, but
-  is not "visible" in the profile's symlink tree.

doc/manual/src/command-ref/files/manifest.nix.md

@@ -1,128 +0,0 @@
-## `manifest.nix`
-
-The manifest file records the provenance of the packages that are installed in a [profile](./profiles.md) managed by [`nix-env`](@docroot@/command-ref/nix-env.md).
-
-Here is an example of how this file might look like after installing `hello` from Nixpkgs:
-
-```nix
-[{
-  meta = {
-    available = true;
-    broken = false;
-    changelog =
-      "https://git.savannah.gnu.org/cgit/hello.git/plain/NEWS?h=v2.12.1";
-    description = "A program that produces a familiar, friendly greeting";
-    homepage = "https://www.gnu.org/software/hello/manual/";
-    insecure = false;
-    license = {
-      deprecated = false;
-      free = true;
-      fullName = "GNU General Public License v3.0 or later";
-      redistributable = true;
-      shortName = "gpl3Plus";
-      spdxId = "GPL-3.0-or-later";
-      url = "https://spdx.org/licenses/GPL-3.0-or-later.html";
-    };
-    longDescription = ''
-      GNU Hello is a program that prints "Hello, world!" when you run it.
-      It is fully customizable.
-    '';
-    maintainers = [{
-      email = "edolstra+nixpkgs@gmail.com";
-      github = "edolstra";
-      githubId = 1148549;
-      name = "Eelco Dolstra";
-    }];
-    name = "hello-2.12.1";
-    outputsToInstall = [ "out" ];
-    platforms = [
-      "i686-cygwin"
-      "x86_64-cygwin"
-      "x86_64-darwin"
-      "i686-darwin"
-      "aarch64-darwin"
-      "armv7a-darwin"
-      "i686-freebsd13"
-      "x86_64-freebsd13"
-      "aarch64-genode"
-      "i686-genode"
-      "x86_64-genode"
-      "x86_64-solaris"
-      "js-ghcjs"
-      "aarch64-linux"
-      "armv5tel-linux"
-      "armv6l-linux"
-      "armv7a-linux"
-      "armv7l-linux"
-      "i686-linux"
-      "m68k-linux"
-      "microblaze-linux"
-      "microblazeel-linux"
-      "mipsel-linux"
-      "mips64el-linux"
-      "powerpc64-linux"
-      "powerpc64le-linux"
-      "riscv32-linux"
-      "riscv64-linux"
-      "s390-linux"
-      "s390x-linux"
-      "x86_64-linux"
-      "mmix-mmixware"
-      "aarch64-netbsd"
-      "armv6l-netbsd"
-      "armv7a-netbsd"
-      "armv7l-netbsd"
-      "i686-netbsd"
-      "m68k-netbsd"
-      "mipsel-netbsd"
-      "powerpc-netbsd"
-      "riscv32-netbsd"
-      "riscv64-netbsd"
-      "x86_64-netbsd"
-      "aarch64_be-none"
-      "aarch64-none"
-      "arm-none"
-      "armv6l-none"
-      "avr-none"
-      "i686-none"
-      "microblaze-none"
-      "microblazeel-none"
-      "msp430-none"
-      "or1k-none"
-      "m68k-none"
-      "powerpc-none"
-      "powerpcle-none"
-      "riscv32-none"
-      "riscv64-none"
-      "rx-none"
-      "s390-none"
-      "s390x-none"
-      "vc4-none"
-      "x86_64-none"
-      "i686-openbsd"
-      "x86_64-openbsd"
-      "x86_64-redox"
-      "wasm64-wasi"
-      "wasm32-wasi"
-      "x86_64-windows"
-      "i686-windows"
-    ];
-    position =
-      "/nix/store/7niq32w715567hbph0q13m5lqna64c1s-nixos-unstable.tar.gz/nixos-unstable.tar.gz/pkgs/applications/misc/hello/default.nix:34";
-    unfree = false;
-    unsupported = false;
-  };
-  name = "hello-2.12.1";
-  out = {
-    outPath = "/nix/store/260q5867crm1xjs4khgqpl6vr9kywql1-hello-2.12.1";
-  };
-  outPath = "/nix/store/260q5867crm1xjs4khgqpl6vr9kywql1-hello-2.12.1";
-  outputs = [ "out" ];
-  system = "x86_64-linux";
-  type = "derivation";
-}]
-```
-
-Each element in this list corresponds to an installed package.
-It incorporates some attributes of the original derivation, including `meta`, `name`, `out`, `outPath`, `outputs`, `system`.
-This information is used by Nix for querying and updating the package.

doc/manual/src/command-ref/files/profiles.md

@@ -1,74 +0,0 @@
-## Profiles
-
-A directory that contains links to profiles managed by [`nix-env`] and [`nix profile`]:
-
-- `$XDG_STATE_HOME/nix/profiles` for regular users
-- `$NIX_STATE_DIR/profiles/per-user/root` if the user is `root`
-
-A profile is a directory of symlinks to files in the Nix store.
-
-### Filesystem layout
-
-Profiles are versioned as follows. When using a profile named *path*, *path* is a symlink to *path*`-`*N*`-link`, where *N* is the version of the profile.
-In turn, *path*`-`*N*`-link` is a symlink to a path in the Nix store.
-For example:
-
-```console
-$ ls -l ~alice/.local/state/nix/profiles/profile*
-lrwxrwxrwx 1 alice users 14 Nov 25 14:35 /home/alice/.local/state/nix/profiles/profile -> profile-7-link
-lrwxrwxrwx 1 alice users 51 Oct 28 16:18 /home/alice/.local/state/nix/profiles/profile-5-link -> /nix/store/q69xad13ghpf7ir87h0b2gd28lafjj1j-profile
-lrwxrwxrwx 1 alice users 51 Oct 29 13:20 /home/alice/.local/state/nix/profiles/profile-6-link -> /nix/store/6bvhpysd7vwz7k3b0pndn7ifi5xr32dg-profile
-lrwxrwxrwx 1 alice users 51 Nov 25 14:35 /home/alice/.local/state/nix/profiles/profile-7-link -> /nix/store/mp0x6xnsg0b8qhswy6riqvimai4gm677-profile
-```
-
-Each of these symlinks is a root for the Nix garbage collector.
-
-The contents of the store path corresponding to each version of the
-profile is a tree of symlinks to the files of the installed packages,
-e.g.
-
-```console
-$ ll -R ~eelco/.local/state/nix/profiles/profile-7-link/
-/home/eelco/.local/state/nix/profiles/profile-7-link/:
-total 20
-dr-xr-xr-x 2 root root 4096 Jan  1  1970 bin
--r--r--r-- 2 root root 1402 Jan  1  1970 manifest.nix
-dr-xr-xr-x 4 root root 4096 Jan  1  1970 share
-
-/home/eelco/.local/state/nix/profiles/profile-7-link/bin:
-total 20
-lrwxrwxrwx 5 root root 79 Jan  1  1970 chromium -> /nix/store/ijm5k0zqisvkdwjkc77mb9qzb35xfi4m-chromium-86.0.4240.111/bin/chromium
-lrwxrwxrwx 7 root root 87 Jan  1  1970 spotify -> /nix/store/w9182874m1bl56smps3m5zjj36jhp3rn-spotify-1.1.26.501.gbe11e53b-15/bin/spotify
-lrwxrwxrwx 3 root root 79 Jan  1  1970 zoom-us -> /nix/store/wbhg2ga8f3h87s9h5k0slxk0m81m4cxl-zoom-us-5.3.469451.0927/bin/zoom-us
-
-/home/eelco/.local/state/nix/profiles/profile-7-link/share/applications:
-total 12
-lrwxrwxrwx 4 root root 120 Jan  1  1970 chromium-browser.desktop -> /nix/store/4cf803y4vzfm3gyk3vzhzb2327v0kl8a-chromium-unwrapped-86.0.4240.111/share/applications/chromium-browser.desktop
-lrwxrwxrwx 7 root root 110 Jan  1  1970 spotify.desktop -> /nix/store/w9182874m1bl56smps3m5zjj36jhp3rn-spotify-1.1.26.501.gbe11e53b-15/share/applications/spotify.desktop
-lrwxrwxrwx 3 root root 107 Jan  1  1970 us.zoom.Zoom.desktop -> /nix/store/wbhg2ga8f3h87s9h5k0slxk0m81m4cxl-zoom-us-5.3.469451.0927/share/applications/us.zoom.Zoom.desktop
-
-…
-```
-
-Each profile version contains a manifest file:
-- [`manifest.nix`](@docroot@/command-ref/files/manifest.nix.md) used by [`nix-env`](@docroot@/command-ref/nix-env.md).
-- [`manifest.json`](@docroot@/command-ref/files/manifest.json.md) used by [`nix profile`](@docroot@/command-ref/new-cli/nix3-profile.md) (experimental).
-
-## User profile link
-
-A symbolic link to the user's current profile:
-
-- `~/.nix-profile`
-- `$XDG_STATE_HOME/nix/profile` if [`use-xdg-base-directories`] is set to `true`.
-
-By default, this symlink points to:
-
-- `$XDG_STATE_HOME/nix/profiles/profile` for regular users
-- `$NIX_STATE_DIR/profiles/per-user/root/profile` for `root`
-
-The `PATH` environment variable should include `/bin` subdirectory of the profile link (e.g. `~/.nix-profile/bin`) for the user environment to be visible to the user.
-The [installer](@docroot@/installation/installing-binary.md) sets this up by default, unless you enable [`use-xdg-base-directories`].
-
-[`nix-env`]: @docroot@/command-ref/nix-env.md
-[`nix profile`]: @docroot@/command-ref/new-cli/nix3-profile.md
-[`use-xdg-base-directories`]: @docroot@/command-ref/conf-file.md#conf-use-xdg-base-directories

doc/manual/src/command-ref/nix-build.md

@@ -51,9 +51,8 @@ derivation).
 
 # Options
 
-All options not listed here are passed to
-[`nix-store --realise`](nix-store/realise.md),
-except for `--arg` and `--attr` / `-A` which are passed to [`nix-instantiate`](nix-instantiate.md).
+All options not listed here are passed to `nix-store --realise`,
+except for `--arg` and `--attr` / `-A` which are passed to `nix-instantiate`.
 
   - <span id="opt-no-out-link">[`--no-out-link`](#opt-no-out-link)<span>
 
@@ -70,8 +69,6 @@ except for `--arg` and `--attr` / `-A` which are passed to [`nix-instantiate`](n
     Change the name of the symlink to the output path created from
     `result` to *outlink*.
 
-{{#include ./status-build-failure.md}}
-
 {{#include ./opt-common.md}}
 
 {{#include ./env-common.md}}
@@ -79,7 +76,7 @@ except for `--arg` and `--attr` / `-A` which are passed to [`nix-instantiate`](n
 # Examples
 
 ```console
-$ nix-build '<nixpkgs>' --attr firefox
+$ nix-build '<nixpkgs>' -A firefox
 store derivation is /nix/store/qybprl8sz2lc...-firefox-1.5.0.7.drv
 /nix/store/d18hyl92g30l...-firefox-1.5.0.7
 
@@ -94,7 +91,7 @@ If a derivation has multiple outputs, `nix-build` will build the default
 (first) output. You can also build all outputs:
 
 ```console
-$ nix-build '<nixpkgs>' --attr openssl.all
+$ nix-build '<nixpkgs>' -A openssl.all
 ```
 
 This will create a symlink for each output named `result-outputname`.
@@ -104,7 +101,7 @@ outputs `out`, `bin` and `man`, `nix-build` will create symlinks
 specific output:
 
 ```console
-$ nix-build '<nixpkgs>' --attr openssl.man
+$ nix-build '<nixpkgs>' -A openssl.man
 ```
 
 This will create a symlink `result-man`.
@@ -112,7 +109,7 @@ This will create a symlink `result-man`.
 Build a Nix expression given on the command line:
 
 ```console
-$ nix-build --expr 'with import <nixpkgs> { }; runCommand "foo" { } "echo bar > $out"'
+$ nix-build -E 'with import <nixpkgs> { }; runCommand "foo" { } "echo bar > $out"'
 $ cat ./result
 bar
 ```
@@ -121,5 +118,5 @@ Build the GNU Hello package from the latest revision of the master
 branch of Nixpkgs:
 
 ```console
-$ nix-build https://github.com/NixOS/nixpkgs/archive/master.tar.gz --attr hello
+$ nix-build https://github.com/NixOS/nixpkgs/archive/master.tar.gz -A hello
 ```

doc/manual/src/command-ref/nix-channel.md

@@ -4,103 +4,97 @@
 
 # Synopsis
 
-`nix-channel` {`--add` url [*name*] | `--remove` *name* | `--list` | `--update` [*names…*] | `--list-generations` | `--rollback` [*generation*] }
+`nix-channel` {`--add` url [*name*] | `--remove` *name* | `--list` | `--update` [*names…*] | `--rollback` [*generation*] }
 
 # Description
 
-Channels are a mechanism for referencing remote Nix expressions and conveniently retrieving their latest version.
+A Nix channel is a mechanism that allows you to automatically stay
+up-to-date with a set of pre-built Nix expressions. A Nix channel is
+just a URL that points to a place containing a set of Nix expressions.
 
-The moving parts of channels are:
-- The official channels listed at <https://nixos.org/channels>
-- The user-specific list of [subscribed channels](#subscribed-channels)
-- The [downloaded channel contents](#channels)
-- The [Nix expression search path](@docroot@/command-ref/conf-file.md#conf-nix-path), set with the [`-I` option](#opt-i) or the [`NIX_PATH` environment variable](#env-NIX_PATH)
-
-> **Note**
->
-> The state of a subscribed channel is external to the Nix expressions relying on it.
-> This may limit reproducibility.
->
-> Dependencies on other Nix expressions can be declared explicitly with:
-> - [`fetchurl`](@docroot@/language/builtins.md#builtins-fetchurl), [`fetchTarball`](@docroot@/language/builtins.md#builtins-fetchTarball), or [`fetchGit`](@docroot@/language/builtins.md#builtins-fetchGit) in Nix expressions
-> - the [`-I` option](@docroot@/command-ref/opt-common.md#opt-I) in command line invocations
+To see the list of official NixOS channels, visit
+<https://nixos.org/channels>.
 
 This command has the following operations:
 
   - `--add` *url* \[*name*\]\
-    Add a channel *name* located at *url* to the list of subscribed channels.
-    If *name* is omitted, default to the last component of *url*, with the suffixes `-stable` or `-unstable` removed.
-
-    > **Note**
-    >
-    > `--add` does not automatically perform an update.
-    > Use `--update` explicitly.
-
-    A channel URL must point to a directory containing a file `nixexprs.tar.gz`.
-    At the top level, that tarball must contain a single directory with a `default.nix` file that serves as the channel’s entry point.
+    Adds a channel named *name* with URL *url* to the list of subscribed
+    channels. If *name* is omitted, it defaults to the last component of
+    *url*, with the suffixes `-stable` or `-unstable` removed.
 
   - `--remove` *name*\
-    Remove the channel *name* from the list of subscribed channels.
+    Removes the channel named *name* from the list of subscribed
+    channels.
 
   - `--list`\
-    Print the names and URLs of all subscribed channels on standard output.
+    Prints the names and URLs of all subscribed channels on standard
+    output.
 
   - `--update` \[*names*…\]\
-    Download the Nix expressions of subscribed channels and create a new generation.
-    Update all channels if none is specified, and only those included in *names* otherwise.
-
-  - `--list-generations`\
-    Prints a list of all the current existing generations for the
-    channel profile.
-
-    Works the same way as
-    ```
-    nix-env --profile /nix/var/nix/profiles/per-user/$USER/channels --list-generations
-    ```
+    Downloads the Nix expressions of all subscribed channels (or only
+    those included in *names* if specified) and makes them the default
+    for `nix-env` operations (by symlinking them from the directory
+    `~/.nix-defexpr`).
 
   - `--rollback` \[*generation*\]\
-    Revert channels to the state before the last call to `nix-channel --update`.
-    Optionally, you can specify a specific channel *generation* number to restore.
+    Reverts the previous call to `nix-channel
+                    --update`. Optionally, you can specify a specific channel generation
+    number to restore.
+
+Note that `--add` does not automatically perform an update.
+
+The list of subscribed channels is stored in `~/.nix-channels`.
 
 {{#include ./opt-common.md}}
 
 {{#include ./env-common.md}}
 
-# Files
-
-`nix-channel` operates on the following files.
-
-{{#include ./files/channels.md}}
-
 # Examples
 
-Subscribe to the Nixpkgs channel and run `hello` from the GNU Hello package:
+To subscribe to the Nixpkgs channel and install the GNU Hello package:
 
 ```console
 $ nix-channel --add https://nixos.org/channels/nixpkgs-unstable
-$ nix-channel --list
-nixpkgs https://nixos.org/channels/nixpkgs
 $ nix-channel --update
-$ nix-shell -p hello --run hello
-hello
+$ nix-env -iA nixpkgs.hello
 ```
 
-Revert channel updates using `--rollback`:
+You can revert channel updates using `--rollback`:
 
 ```console
-$ nix-instantiate --eval '<nixpkgs>' --attr lib.version
-"22.11pre296212.530a53dcbc9"
+$ nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'
+"14.04.527.0e935f1"
 
 $ nix-channel --rollback
 switching from generation 483 to 482
 
-$ nix-instantiate --eval '<nixpkgs>' --attr lib.version
-"22.11pre281526.d0419badfad"
+$ nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'
+"14.04.526.dbadfad"
 ```
 
-Remove a channel:
+# Files
 
-```console
-$ nix-channel --remove nixpkgs
-$ nix-channel --list
-```
+  - `${XDG_STATE_HOME-$HOME/.local/state}/nix/profiles/channels`\
+    `nix-channel` uses a `nix-env` profile to keep track of previous
+    versions of the subscribed channels. Every time you run `nix-channel
+    --update`, a new channel generation (that is, a symlink to the
+    channel Nix expressions in the Nix store) is created. This enables
+    `nix-channel --rollback` to revert to previous versions.
+
+  - `~/.nix-defexpr/channels`\
+    This is a symlink to
+    `${XDG_STATE_HOME-$HOME/.local/state}/nix/profiles/channels`. It ensures that
+    `nix-env` can find your channels. In a multi-user installation, you
+    may also have `~/.nix-defexpr/channels_root`, which links to the
+    channels of the root user.
+
+# Channel format
+
+A channel URL should point to a directory containing the following
+files:
+
+  - `nixexprs.tar.xz`\
+    A tarball containing Nix expressions and files referenced by them
+    (such as build scripts and patches). At the top level, the tarball
+    should contain a single directory. That directory must contain a
+    file `default.nix` that serves as the channel’s “entry point”.

doc/manual/src/command-ref/nix-collect-garbage.md

@@ -1,6 +1,6 @@
 # Name
 
-`nix-collect-garbage` - delete unreachable [store objects]
+`nix-collect-garbage` - delete unreachable store paths
 
 # Synopsis
 
@@ -8,57 +8,17 @@
 
 # Description
 
-The command `nix-collect-garbage` is mostly an alias of [`nix-store --gc`](@docroot@/command-ref/nix-store/gc.md).
-That is, it deletes all unreachable [store objects] in the Nix store to clean up your system.
-
-However, it provides two additional options,
-[`--delete-old`](#opt-delete-old) and [`--delete-older-than`](#opt-delete-older-than),
-which also delete old [profiles], allowing potentially more [store objects] to be deleted because profiles are also garbage collection roots.
-These options are the equivalent of running
-[`nix-env --delete-generations`](@docroot@/command-ref/nix-env/delete-generations.md)
-with various augments on multiple profiles,
-prior to running `nix-collect-garbage` (or just `nix-store --gc`) without any flags.
-
-> **Note**
->
-> Deleting previous configurations makes rollbacks to them impossible.
-
-These flags should be used with care, because they potentially delete generations of profiles used by other users on the system.
-
-## Locations searched for profiles
-
-`nix-collect-garbage` cannot know about all profiles; that information doesn't exist.
-Instead, it looks in a few locations, and acts on all profiles it finds there:
-
-1. The default profile locations as specified in the [profiles] section of the manual.
-
-2. > **NOTE**
-   >
-   > Not stable; subject to change
-   >
-   > Do not rely on this functionality; it just exists for migration purposes and is may change in the future.
-   > These deprecated paths remain a private implementation detail of Nix.
-
-   `$NIX_STATE_DIR/profiles` and `$NIX_STATE_DIR/profiles/per-user`.
-
-   With the exception of `$NIX_STATE_DIR/profiles/per-user/root` and `$NIX_STATE_DIR/profiles/default`, these directories are no longer used by other commands.
-   `nix-collect-garbage` looks there anyways in order to clean up profiles from older versions of Nix.
-
-# Options
-
-These options are for deleting old [profiles] prior to deleting unreachable [store objects].
-
-- <span id="opt-delete-old">[`--delete-old`](#opt-delete-old)</span> / `-d`\
-  Delete all old generations of profiles.
-
-  This is the equivalent of invoking `nix-env --delete-generations old` on each found profile.
-
-- <span id="opt-delete-older-than">[`--delete-older-than`](#opt-delete-older-than)</span> *period*\
-  Delete all generations of profiles older than the specified amount (except for the generations that were active at that point in time).
-  *period* is a value such as `30d`, which would mean 30 days.
-
-  This is the equivalent of invoking [`nix-env --delete-generations <period>`](@docroot@/command-ref/nix-env/delete-generations.md#generations-time) on each found profile.
-  See the documentation of that command for additional information about the *period* argument.
+The command `nix-collect-garbage` is mostly an alias of [`nix-store
+--gc`](@docroot@/command-ref/nix-store/gc.md), that is, it deletes all
+unreachable paths in the Nix store to clean up your system. However,
+it provides two additional options: `-d` (`--delete-old`), which
+deletes all old generations of all profiles in `/nix/var/nix/profiles`
+by invoking `nix-env --delete-generations old` on all profiles (of
+course, this makes rollbacks to previous configurations impossible);
+and `--delete-older-than` *period*, where period is a value such as
+`30d`, which deletes all generations older than the specified number
+of days in all profiles in `/nix/var/nix/profiles` (except for the
+generations that were active at that point in time).
 
 {{#include ./opt-common.md}}
 
@@ -72,6 +32,3 @@ generations of each profile, do
 ```console
 $ nix-collect-garbage -d
 ```
-
-[profiles]: @docroot@/command-ref/files/profiles.md
-[store objects]: @docroot@/glossary.md#gloss-store-object

doc/manual/src/command-ref/nix-copy-closure.md

@@ -87,5 +87,5 @@ environment:
 ```console
 $ nix-copy-closure --from alice@itchy.labs \
     /nix/store/0dj0503hjxy5mbwlafv1rsbdiyx1gkdy-subversion-1.4.4
-$ nix-env --install /nix/store/0dj0503hjxy5mbwlafv1rsbdiyx1gkdy-subversion-1.4.4
+$ nix-env -i /nix/store/0dj0503hjxy5mbwlafv1rsbdiyx1gkdy-subversion-1.4.4
 ```

doc/manual/src/command-ref/nix-env.md

@@ -49,7 +49,7 @@ These pages can be viewed offline:
 
 # Selectors
 
-Several commands, such as `nix-env --query ` and `nix-env --install `, take a list of
+Several commands, such as `nix-env -q` and `nix-env -i`, take a list of
 arguments that specify the packages on which to operate. These are
 extended regular expressions that must match the entire name of the
 package. (For details on regular expressions, see **regex**(7).) The match is
@@ -83,8 +83,46 @@ match. Here are some examples:
 
 # Files
 
-`nix-env` operates on the following files.
+  - `~/.nix-defexpr`\
+    The source for the default Nix expressions used by the
+    `--install`, `--upgrade`, and `--query --available` operations to
+    obtain derivations. The `--file` option may be used to override
+    this default.
 
-{{#include ./files/default-nix-expression.md}}
+    If `~/.nix-defexpr` is a file, it is loaded as a Nix expression. If
+    the expression is a set, it is used as the default Nix expression.
+    If the expression is a function, an empty set is passed as argument
+    and the return value is used as the default Nix expression.
 
-{{#include ./files/profiles.md}}
+    If `~/.nix-defexpr` is a directory containing a `default.nix` file,
+    that file is loaded as in the above paragraph.
+
+    If `~/.nix-defexpr` is a directory without a `default.nix` file,
+    then its contents (both files and subdirectories) are loaded as Nix
+    expressions. The expressions are combined into a single set, each
+    expression under an attribute with the same name as the original
+    file or subdirectory.
+
+    For example, if `~/.nix-defexpr` contains two files, `foo.nix` and
+    `bar.nix`, then the default Nix expression will essentially be
+
+    ```nix
+    {
+      foo = import ~/.nix-defexpr/foo.nix;
+      bar = import ~/.nix-defexpr/bar.nix;
+    }
+    ```
+
+    The file `manifest.nix` is always ignored. Subdirectories without a
+    `default.nix` file are traversed recursively in search of more Nix
+    expressions, but the names of these intermediate directories are not
+    added to the attribute paths of the default Nix expression.
+
+    The command `nix-channel` places symlinks to the downloaded Nix
+    expressions from each subscribed channel in this directory.
+
+  - `~/.nix-profile`\
+    A symbolic link to the user's current profile. By default, this
+    symlink points to `prefix/var/nix/profiles/default`. The `PATH`
+    environment variable should include `~/.nix-profile/bin` for the
+    user environment to be visible to the user.

doc/manual/src/command-ref/nix-env/delete-generations.md

@@ -9,47 +9,14 @@
 # Description
 
 This operation deletes the specified generations of the current profile.
-
-*generations* can be a one of the following:
-
-- <span id="generations-list">`<number>...`</span>:\
-  A list of generation numbers, each one a separate command-line argument.
-
-  Delete exactly the profile generations given by their generation number.
-  Deleting the current generation is not allowed.
-
-- The special value <span id="generations-old">`old`</span>
-
-  Delete all generations except the current one.
-
-  > **WARNING**
-  >
-  > Older *and newer* generations will be deleted by this operation.
-  >
-  > One might expect this to just delete older generations than the curent one, but that is only true if the current generation is also the latest.
-  > Because one can roll back to a previous generation, it is possible to have generations newer than the current one.
-  > They will also be deleted.
-
-- <span id="generations-time">`<number>d`</span>:\
-  The last *number* days
-
-  *Example*: `30d`
-
-  Delete all generations created more than *number* days ago, except the most recent one of them.
-  This allows rolling back to generations that were available within the specified period.
-
-- <span id="generations-count">`+<number>`</span>:\
-  The last *number* generations up to the present
-
-  *Example*: `+5`
-
-  Keep the last *number* generations, along with any newer than current.
-
-Periodically deleting old generations is important to make garbage collection
-effective.
-The is because profiles are also garbage collection roots — any [store object] reachable from a profile is "alive" and ineligible for deletion.
-
-[store object]: @docroot@/glossary.md#gloss-store-object
+The generations can be a list of generation numbers, the special value
+`old` to delete all non-current generations, a value such as `30d` to
+delete all generations older than the specified number of days (except
+for the generation that was active at that point in time), or a value
+such as `+5` to keep the last `5` generations ignoring any newer than
+current, e.g., if `30` is the current generation `+5` will delete
+generation `25` and all older generations. Periodically deleting old
+generations is important to make garbage collection effective.
 
 {{#include ./opt-common.md}}
 
@@ -61,35 +28,19 @@ The is because profiles are also garbage collection roots — any [store object]
 
 # Examples
 
-## Delete explicit generation numbers
-
 ```console
 $ nix-env --delete-generations 3 4 8
 ```
 
-Delete the generations numbered 3, 4, and 8, so long as the current active generation is not any of those.
-
-## Keep most-recent by count (number of generations)
-
 ```console
 $ nix-env --delete-generations +5
 ```
 
-Suppose `30` is the current generation, and we currently have generations numbered `20` through `32`.
-
-Then this command will delete generations `20` through `25` (`<= 30 - 5`),
-and keep generations `26` through `31` (`> 30 - 5`).
-
-## Keep most-recent by time (number of days)
-
 ```console
 $ nix-env --delete-generations 30d
 ```
 
-This command will delete all generations older than 30 days, except for the generation that was active 30 days ago (if it currently exists).
-
-## Delete all older
-
 ```console
-$ nix-env --profile other_profile --delete-generations old
+$ nix-env -p other_profile --delete-generations old
 ```
+

doc/manual/src/command-ref/nix-env/install.md

@@ -30,13 +30,13 @@ a number of possible ways:
     derivation with the highest *priority* is used. A derivation can
     define a priority by declaring the `meta.priority` attribute. This
     attribute should be a number, with a higher value denoting a lower
-    priority. The default priority is `5`.
+    priority. The default priority is `0`.
 
     If there are multiple matching derivations with the same priority,
     then the derivation with the highest version will be installed.
 
     You can force the installation of multiple derivations with the same
-    name by being specific about the versions. For instance, `nix-env --install
+    name by being specific about the versions. For instance, `nix-env -i
     gcc-3.3.6 gcc-4.1.1` will install both version of GCC (and will
     probably cause a user environment conflict\!).
 
@@ -44,7 +44,7 @@ a number of possible ways:
     paths* that select attributes from the top-level Nix
     expression. This is faster than using derivation names and
     unambiguous. To find out the attribute paths of available
-    packages, use `nix-env --query --available --attr-path `.
+    packages, use `nix-env -qaP`.
 
   - If `--from-profile` *path* is given, *args* is a set of names
     denoting installed store paths in the profile *path*. This is an
@@ -87,7 +87,7 @@ a number of possible ways:
 
   - `--remove-all` / `-r`\
     Remove all previously installed packages first. This is equivalent
-    to running `nix-env --uninstall '.*'` first, except that everything happens
+    to running `nix-env -e '.*'` first, except that everything happens
     in a single transaction.
 
 {{#include ./opt-common.md}}
@@ -103,9 +103,9 @@ a number of possible ways:
 To install a package using a specific attribute path from the active Nix expression:
 
 ```console
-$ nix-env --install --attr gcc40mips
+$ nix-env -iA gcc40mips
 installing `gcc-4.0.2'
-$ nix-env --install --attr xorg.xorgserver
+$ nix-env -iA xorg.xorgserver
 installing `xorg-server-1.2.0'
 ```
 
@@ -133,32 +133,32 @@ installing `gcc-3.3.2'
 To install all derivations in the Nix expression `foo.nix`:
 
 ```console
-$ nix-env --file ~/foo.nix --install '.*'
+$ nix-env -f ~/foo.nix -i '.*'
 ```
 
 To copy the store path with symbolic name `gcc` from another profile:
 
 ```console
-$ nix-env --install --from-profile /nix/var/nix/profiles/foo gcc
+$ nix-env -i --from-profile /nix/var/nix/profiles/foo gcc
 ```
 
 To install a specific [store derivation] (typically created by
 `nix-instantiate`):
 
 ```console
-$ nix-env --install /nix/store/fibjb1bfbpm5mrsxc4mh2d8n37sxh91i-gcc-3.4.3.drv
+$ nix-env -i /nix/store/fibjb1bfbpm5mrsxc4mh2d8n37sxh91i-gcc-3.4.3.drv
 ```
 
 To install a specific output path:
 
 ```console
-$ nix-env --install /nix/store/y3cgx0xj1p4iv9x0pnnmdhr8iyg741vk-gcc-3.4.3
+$ nix-env -i /nix/store/y3cgx0xj1p4iv9x0pnnmdhr8iyg741vk-gcc-3.4.3
 ```
 
 To install from a Nix expression specified on the command-line:
 
 ```console
-$ nix-env --file ./foo.nix --install --expr \
+$ nix-env -f ./foo.nix -i -E \
     'f: (f {system = "i686-linux";}).subversionWithJava'
 ```
 
@@ -170,7 +170,7 @@ function defined in `./foo.nix`.
 A dry-run tells you which paths will be downloaded or built from source:
 
 ```console
-$ nix-env --file '<nixpkgs>' --install --attr hello --dry-run
+$ nix-env -f '<nixpkgs>' -iA hello --dry-run
 (dry run; not doing anything)
 installing ‘hello-2.10’
 this path will be fetched (0.04 MiB download, 0.19 MiB unpacked):
@@ -182,6 +182,6 @@ To install Firefox from the latest revision in the Nixpkgs/NixOS 14.12
 channel:
 
 ```console
-$ nix-env --file https://github.com/NixOS/nixpkgs/archive/nixos-14.12.tar.gz --install --attr firefox
+$ nix-env -f https://github.com/NixOS/nixpkgs/archive/nixos-14.12.tar.gz -iA firefox
 ```
 

doc/manual/src/command-ref/nix-env/query.md

@@ -137,7 +137,7 @@ derivation is shown unless `--no-name` is specified.
 To show installed packages:
 
 ```console
-$ nix-env --query
+$ nix-env -q
 bison-1.875c
 docbook-xml-4.2
 firefox-1.0.4
@@ -149,7 +149,7 @@ ORBit2-2.8.3
 To show available packages:
 
 ```console
-$ nix-env --query --available
+$ nix-env -qa
 firefox-1.0.7
 GConf-2.4.0.1
 MPlayer-1.0pre7
@@ -160,7 +160,7 @@ ORBit2-2.8.3
 To show the status of available packages:
 
 ```console
-$ nix-env --query --available --status
+$ nix-env -qas
 -P- firefox-1.0.7   (not installed but present)
 --S GConf-2.4.0.1   (not present, but there is a substitute for fast installation)
 --S MPlayer-1.0pre3 (i.e., this is not the installed MPlayer, even though the version is the same!)
@@ -171,14 +171,14 @@ IP- ORBit2-2.8.3    (installed and by definition present)
 To show available packages in the Nix expression `foo.nix`:
 
 ```console
-$ nix-env --file ./foo.nix --query --available
+$ nix-env -f ./foo.nix -qa
 foo-1.2.3
 ```
 
 To compare installed versions to what’s available:
 
 ```console
-$ nix-env --query --compare-versions
+$ nix-env -qc
 ...
 acrobat-reader-7.0 - ?      (package is not available at all)
 autoconf-2.59      = 2.59   (same version)
@@ -189,7 +189,7 @@ firefox-1.0.4      < 1.0.7  (a more recent version is available)
 To show all packages with “`zip`” in the name:
 
 ```console
-$ nix-env --query --available '.*zip.*'
+$ nix-env -qa '.*zip.*'
 bzip2-1.0.6
 gzip-1.6
 zip-3.0
@@ -199,7 +199,7 @@ zip-3.0
 To show all packages with “`firefox`” or “`chromium`” in the name:
 
 ```console
-$ nix-env --query --available '.*(firefox|chromium).*'
+$ nix-env -qa '.*(firefox|chromium).*'
 chromium-37.0.2062.94
 chromium-beta-38.0.2125.24
 firefox-32.0.3
@@ -210,6 +210,6 @@ firefox-with-plugins-13.0.1
 To show all packages in the latest revision of the Nixpkgs repository:
 
 ```console
-$ nix-env --file https://github.com/NixOS/nixpkgs/archive/master.tar.gz --query --available
+$ nix-env -f https://github.com/NixOS/nixpkgs/archive/master.tar.gz -qa
 ```
 

doc/manual/src/command-ref/nix-env/set-flag.md

@@ -46,16 +46,16 @@ To prevent the currently installed Firefox from being upgraded:
 $ nix-env --set-flag keep true firefox
 ```
 
-After this, `nix-env --upgrade ` will ignore Firefox.
+After this, `nix-env -u` will ignore Firefox.
 
 To disable the currently installed Firefox, then install a new Firefox
 while the old remains part of the profile:
 
 ```console
-$ nix-env --query
+$ nix-env -q
 firefox-2.0.0.9 (the current one)
 
-$ nix-env --preserve-installed --install firefox-2.0.0.11
+$ nix-env --preserve-installed -i firefox-2.0.0.11
 installing `firefox-2.0.0.11'
 building path(s) `/nix/store/myy0y59q3ig70dgq37jqwg1j0rsapzsl-user-environment'
 collision between `/nix/store/...-firefox-2.0.0.11/bin/firefox'
@@ -65,10 +65,10 @@ collision between `/nix/store/...-firefox-2.0.0.11/bin/firefox'
 $ nix-env --set-flag active false firefox
 setting flag on `firefox-2.0.0.9'
 
-$ nix-env --preserve-installed --install firefox-2.0.0.11
+$ nix-env --preserve-installed -i firefox-2.0.0.11
 installing `firefox-2.0.0.11'
 
-$ nix-env --query
+$ nix-env -q
 firefox-2.0.0.11 (the enabled one)
 firefox-2.0.0.9 (the disabled one)
 ```

doc/manual/src/command-ref/nix-env/set.md

@@ -25,6 +25,6 @@ The following updates a profile such that its current generation will
 contain just Firefox:
 
 ```console
-$ nix-env --profile /nix/var/nix/profiles/browser --set firefox
+$ nix-env -p /nix/var/nix/profiles/browser --set firefox
 ```
 

doc/manual/src/command-ref/nix-env/switch-generation.md

@@ -27,7 +27,7 @@ Switching will fail if the specified generation does not exist.
 # Examples
 
 ```console
-$ nix-env --switch-generation 42
+$ nix-env -G 42
 switching from generation 50 to 42
 ```
 

doc/manual/src/command-ref/nix-env/switch-profile.md

@@ -22,5 +22,5 @@ the symlink `~/.nix-profile` is made to point to *path*.
 # Examples
 
 ```console
-$ nix-env --switch-profile ~/my-profile
+$ nix-env -S ~/my-profile
 ```

doc/manual/src/command-ref/nix-env/uninstall.md

@@ -24,5 +24,5 @@ designated by the symbolic names *drvnames* are removed.
 
 ```console
 $ nix-env --uninstall gcc
-$ nix-env --uninstall '.*' (remove everything)
+$ nix-env -e '.*' (remove everything)
 ```

doc/manual/src/command-ref/nix-env/upgrade.md

@@ -76,21 +76,21 @@ version is installed.
 # Examples
 
 ```console
-$ nix-env --upgrade --attr nixpkgs.gcc
+$ nix-env --upgrade -A nixpkgs.gcc
 upgrading `gcc-3.3.1' to `gcc-3.4'
 ```
 
 When there are no updates available, nothing will happen:
 
 ```console
-$ nix-env --upgrade --attr nixpkgs.pan
+$ nix-env --upgrade -A nixpkgs.pan
 ```
 
 Using `-A` is preferred when possible, as it is faster and unambiguous but
 it is also possible to upgrade to a specific version by matching the derivation name:
 
 ```console
-$ nix-env --upgrade gcc-3.3.2 --always
+$ nix-env -u gcc-3.3.2 --always
 upgrading `gcc-3.4' to `gcc-3.3.2'
 ```
 
@@ -98,7 +98,7 @@ To try to upgrade everything
 (matching packages based on the part of the derivation name without version):
 
 ```console
-$ nix-env --upgrade
+$ nix-env -u
 upgrading `hello-2.1.2' to `hello-2.1.3'
 upgrading `mozilla-1.2' to `mozilla-1.4'
 ```

doc/manual/src/command-ref/nix-instantiate.md

@@ -88,7 +88,7 @@ Instantiate [store derivation]s from a Nix expression, and build them using `nix
 $ nix-instantiate test.nix (instantiate)
 /nix/store/cigxbmvy6dzix98dxxh9b6shg7ar5bvs-perl-BerkeleyDB-0.26.drv
 
-$ nix-store --realise $(nix-instantiate test.nix) (build)
+$ nix-store -r $(nix-instantiate test.nix) (build)
 ...
 /nix/store/qhqk4n8ci095g3sdp93x7rgwyh9rdvgk-perl-BerkeleyDB-0.26 (output path)
 
@@ -100,30 +100,30 @@ dr-xr-xr-x    2 eelco    users        4096 1970-01-01 01:00 lib
 You can also give a Nix expression on the command line:
 
 ```console
-$ nix-instantiate --expr 'with import <nixpkgs> { }; hello'
+$ nix-instantiate -E 'with import <nixpkgs> { }; hello'
 /nix/store/j8s4zyv75a724q38cb0r87rlczaiag4y-hello-2.8.drv
 ```
 
 This is equivalent to:
 
 ```console
-$ nix-instantiate '<nixpkgs>' --attr hello
+$ nix-instantiate '<nixpkgs>' -A hello
 ```
 
 Parsing and evaluating Nix expressions:
 
 ```console
-$ nix-instantiate --parse --expr '1 + 2'
+$ nix-instantiate --parse -E '1 + 2'
 1 + 2
 ```
 
 ```console
-$ nix-instantiate --eval --expr '1 + 2'
+$ nix-instantiate --eval -E '1 + 2'
 3
 ```
 
 ```console
-$ nix-instantiate --eval --xml --expr '1 + 2'
+$ nix-instantiate --eval --xml -E '1 + 2'
 <?xml version='1.0' encoding='utf-8'?>
 <expr>
   <int value="3" />
@@ -133,7 +133,7 @@ $ nix-instantiate --eval --xml --expr '1 + 2'
 The difference between non-strict and strict evaluation:
 
 ```console
-$ nix-instantiate --eval --xml --expr 'rec { x = "foo"; y = x; }'
+$ nix-instantiate --eval --xml -E 'rec { x = "foo"; y = x; }'
 ...
   <attr name="x">
     <string value="foo" />
@@ -148,7 +148,7 @@ Note that `y` is left unevaluated (the XML representation doesn’t
 attempt to show non-normal forms).
 
 ```console
-$ nix-instantiate --eval --xml --strict --expr 'rec { x = "foo"; y = x; }'
+$ nix-instantiate --eval --xml --strict -E 'rec { x = "foo"; y = x; }'
 ...
   <attr name="x">
     <string value="foo" />

doc/manual/src/command-ref/nix-prefetch-url.md

@@ -31,18 +31,15 @@ store already contains a file with the same hash and base name.
 Otherwise, the file is downloaded, and an error is signaled if the
 actual hash of the file does not match the specified hash.
 
-This command prints the hash on standard output.
-The hash is printed using base-32 unless `--type md5` is specified,
-in which case it's printed using base-16.
-Additionally, if the option `--print-path` is used,
-the path of the downloaded file in the Nix store is also printed.
+This command prints the hash on standard output. Additionally, if the
+option `--print-path` is used, the path of the downloaded file in the
+Nix store is also printed.
 
 # Options
 
   - `--type` *hashAlgo*\
-    Use the specified cryptographic hash algorithm,
-    which can be one of `md5`, `sha1`, `sha256`, and `sha512`.
-    The default is `sha256`.
+    Use the specified cryptographic hash algorithm, which can be one of
+    `md5`, `sha1`, `sha256`, and `sha512`.
 
   - `--print-path`\
     Print the store path of the downloaded file on standard output.

doc/manual/src/command-ref/nix-shell.md

@@ -89,7 +89,7 @@ All options not listed here are passed to `nix-store
   - `--packages` / `-p` *packages*…\
     Set up an environment in which the specified packages are present.
     The command line arguments are interpreted as attribute names inside
-    the Nix Packages collection. Thus, `nix-shell --packages libjpeg openjdk`
+    the Nix Packages collection. Thus, `nix-shell -p libjpeg openjdk`
     will start a shell in which the packages denoted by the attribute
     names `libjpeg` and `openjdk` are present.
 
@@ -118,7 +118,7 @@ To build the dependencies of the package Pan, and start an interactive
 shell in which to build it:
 
 ```console
-$ nix-shell '<nixpkgs>' --attr pan
+$ nix-shell '<nixpkgs>' -A pan
 [nix-shell]$ eval ${unpackPhase:-unpackPhase}
 [nix-shell]$ cd $sourceRoot
 [nix-shell]$ eval ${patchPhase:-patchPhase}
@@ -137,7 +137,7 @@ To clear the environment first, and do some additional automatic
 initialisation of the interactive shell:
 
 ```console
-$ nix-shell '<nixpkgs>' --attr pan --pure \
+$ nix-shell '<nixpkgs>' -A pan --pure \
     --command 'export NIX_DEBUG=1; export NIX_CORES=8; return'
 ```
 
@@ -146,13 +146,13 @@ Nix expressions can also be given on the command line using the `-E` and
 packages `sqlite` and `libX11`:
 
 ```console
-$ nix-shell --expr 'with import <nixpkgs> { }; runCommand "dummy" { buildInputs = [ sqlite xorg.libX11 ]; } ""'
+$ nix-shell -E 'with import <nixpkgs> { }; runCommand "dummy" { buildInputs = [ sqlite xorg.libX11 ]; } ""'
 ```
 
 A shorter way to do the same is:
 
 ```console
-$ nix-shell --packages sqlite xorg.libX11
+$ nix-shell -p sqlite xorg.libX11
 [nix-shell]$ echo $NIX_LDFLAGS
 … -L/nix/store/j1zg5v…-sqlite-3.8.0.2/lib -L/nix/store/0gmcz9…-libX11-1.6.1/lib …
 ```
@@ -162,7 +162,7 @@ the `buildInputs = [ ... ]` shown above, not only package names. So the
 following is also legal:
 
 ```console
-$ nix-shell --packages sqlite 'git.override { withManual = false; }'
+$ nix-shell -p sqlite 'git.override { withManual = false; }'
 ```
 
 The `-p` flag looks up Nixpkgs in the Nix search path. You can override
@@ -171,7 +171,7 @@ gives you a shell containing the Pan package from a specific revision of
 Nixpkgs:
 
 ```console
-$ nix-shell --packages pan -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/8a3eea054838b55aca962c3fbde9c83c102b8bf2.tar.gz
+$ nix-shell -p pan -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/8a3eea054838b55aca962c3fbde9c83c102b8bf2.tar.gz
 
 [nix-shell:~]$ pan --version
 Pan 0.139
@@ -185,7 +185,7 @@ done by starting the script with the following lines:
 
 ```bash
 #! /usr/bin/env nix-shell
-#! nix-shell -i real-interpreter --packages packages
+#! nix-shell -i real-interpreter -p packages
 ```
 
 where *real-interpreter* is the “real” script interpreter that will be
@@ -202,7 +202,7 @@ For example, here is a Python script that depends on Python and the
 
 ```python
 #! /usr/bin/env nix-shell
-#! nix-shell -i python --packages python pythonPackages.prettytable
+#! nix-shell -i python -p python pythonPackages.prettytable
 
 import prettytable
 
@@ -217,7 +217,7 @@ requires Perl and the `HTML::TokeParser::Simple` and `LWP` packages:
 
 ```perl
 #! /usr/bin/env nix-shell
-#! nix-shell -i perl --packages perl perlPackages.HTMLTokeParserSimple perlPackages.LWP
+#! nix-shell -i perl -p perl perlPackages.HTMLTokeParserSimple perlPackages.LWP
 
 use HTML::TokeParser::Simple;
 
@@ -235,7 +235,7 @@ package like Terraform:
 
 ```bash
 #! /usr/bin/env nix-shell
-#! nix-shell -i bash --packages "terraform.withPlugins (plugins: [ plugins.openstack ])"
+#! nix-shell -i bash -p "terraform.withPlugins (plugins: [ plugins.openstack ])"
 
 terraform apply
 ```
@@ -251,7 +251,7 @@ branch):
 
 ```haskell
 #! /usr/bin/env nix-shell
-#! nix-shell -i runghc --packages "haskellPackages.ghcWithPackages (ps: [ps.download-curl ps.tagsoup])"
+#! nix-shell -i runghc -p "haskellPackages.ghcWithPackages (ps: [ps.download-curl ps.tagsoup])"
 #! nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixos-20.03.tar.gz
 
 import Network.Curl.Download

doc/manual/src/command-ref/nix-store/dump.md

@@ -23,7 +23,7 @@ produce the same NAR archive. For instance, directory entries are
 always sorted so that the actual on-disk order doesn’t influence the
 result.  This means that the cryptographic hash of a NAR dump of a
 path is usable as a fingerprint of the contents of the path. Indeed,
-the hashes of store paths stored in Nix’s database (see `nix-store --query
+the hashes of store paths stored in Nix’s database (see `nix-store -q
 --hash`) are SHA-256 hashes of the NAR dump of each store path.
 
 NAR archives support filenames of unlimited length and 64-bit file

doc/manual/src/command-ref/nix-store/export.md

@@ -31,7 +31,7 @@ To copy a whole closure, do something
 like:
 
 ```console
-$ nix-store --export $(nix-store --query --requisites paths) > out
+$ nix-store --export $(nix-store -qR paths) > out
 ```
 
 To import the whole closure again, run:

doc/manual/src/command-ref/nix-store/opt-common.md

@@ -11,7 +11,7 @@ The following options are allowed for all `nix-store` operations, but may not al
   be created in `/nix/var/nix/gcroots/auto/`. For instance,
 
   ```console
-  $ nix-store --add-root /home/eelco/bla/result --realise ...
+  $ nix-store --add-root /home/eelco/bla/result -r ...
 
   $ ls -l /nix/var/nix/gcroots/auto
   lrwxrwxrwx    1 ... 2005-03-13 21:10 dn54lcypm8f8... -> /home/eelco/bla/result

doc/manual/src/command-ref/nix-store/query.md

@@ -5,8 +5,8 @@
 # Synopsis
 
 `nix-store` {`--query` | `-q`}
-  {`--outputs` | `--requisites` | `-R` | `--references` | `--referrers` |
-  `--referrers-closure` | `--deriver` | `-d` | `--valid-derivers` |
+  {`--outputs` | `--requisites` | `-R` | `--references` |
+  `--referrers` | `--referrers-closure` | `--deriver` | `-d` |
   `--graph` | `--tree` | `--binding` *name* | `-b` *name* | `--hash` |
   `--size` | `--roots`}
   [`--use-output`] [`-u`] [`--force-realise`] [`-f`]
@@ -82,21 +82,13 @@ symlink.
     in the Nix store that are dependent on *paths*.
 
   - `--deriver`; `-d`\
-    Prints the [deriver] that was used to build the store paths *paths*. If
+    Prints the [deriver] of the store paths *paths*. If
     the path has no deriver (e.g., if it is a source file), or if the
     deriver is not known (e.g., in the case of a binary-only
     deployment), the string `unknown-deriver` is printed.
-    The returned deriver is not guaranteed to exist in the local store, for
-    example when *paths* were substituted from a binary cache.
-    Use `--valid-derivers` instead to obtain valid paths only.
 
     [deriver]: ../../glossary.md#gloss-deriver
 
-  - `--valid-derivers`\
-    Prints a set of derivation files (`.drv`) which are supposed produce
-    said paths when realized. Might print nothing, for example for source paths
-    or paths subsituted from a binary cache.
-
   - `--graph`\
     Prints the references graph of the store paths *paths* in the format
     of the `dot` tool of AT\&T's [Graphviz
@@ -153,7 +145,7 @@ Print the closure (runtime dependencies) of the `svn` program in the
 current user environment:
 
 ```console
-$ nix-store --query --requisites $(which svn)
+$ nix-store -qR $(which svn)
 /nix/store/5mbglq5ldqld8sj57273aljwkfvj22mc-subversion-1.1.4
 /nix/store/9lz9yc6zgmc0vlqmn2ipcpkjlmbi51vv-glibc-2.3.4
 ...
@@ -162,7 +154,7 @@ $ nix-store --query --requisites $(which svn)
 Print the build-time dependencies of `svn`:
 
 ```console
-$ nix-store --query --requisites $(nix-store --query --deriver $(which svn))
+$ nix-store -qR $(nix-store -qd $(which svn))
 /nix/store/02iizgn86m42q905rddvg4ja975bk2i4-grep-2.5.1.tar.bz2.drv
 /nix/store/07a2bzxmzwz5hp58nf03pahrv2ygwgs3-gcc-wrapper.sh
 /nix/store/0ma7c9wsbaxahwwl04gbw3fcd806ski4-glibc-2.3.4.drv
@@ -176,7 +168,7 @@ the derivation (`-qd`), not the closure of the output path that contains
 Show the build-time dependencies as a tree:
 
 ```console
-$ nix-store --query --tree $(nix-store --query --deriver $(which svn))
+$ nix-store -q --tree $(nix-store -qd $(which svn))
 /nix/store/7i5082kfb6yjbqdbiwdhhza0am2xvh6c-subversion-1.1.4.drv
 +---/nix/store/d8afh10z72n8l1cr5w42366abiblgn54-builder.sh
 +---/nix/store/fmzxmpjx2lh849ph0l36snfj9zdibw67-bash-3.0.drv
@@ -188,7 +180,7 @@ $ nix-store --query --tree $(nix-store --query --deriver $(which svn))
 Show all paths that depend on the same OpenSSL library as `svn`:
 
 ```console
-$ nix-store --query --referrers $(nix-store --query --binding openssl $(nix-store --query --deriver $(which svn)))
+$ nix-store -q --referrers $(nix-store -q --binding openssl $(nix-store -qd $(which svn)))
 /nix/store/23ny9l9wixx21632y2wi4p585qhva1q8-sylpheed-1.0.0
 /nix/store/5mbglq5ldqld8sj57273aljwkfvj22mc-subversion-1.1.4
 /nix/store/dpmvp969yhdqs7lm2r1a3gng7pyq6vy4-subversion-1.1.3
@@ -199,7 +191,7 @@ Show all paths that directly or indirectly depend on the Glibc (C
 library) used by `svn`:
 
 ```console
-$ nix-store --query --referrers-closure $(ldd $(which svn) | grep /libc.so | awk '{print $3}')
+$ nix-store -q --referrers-closure $(ldd $(which svn) | grep /libc.so | awk '{print $3}')
 /nix/store/034a6h4vpz9kds5r6kzb9lhh81mscw43-libgnomeprintui-2.8.2
 /nix/store/15l3yi0d45prm7a82pcrknxdh6nzmxza-gawk-3.1.4
 ...
@@ -212,7 +204,7 @@ Make a picture of the runtime dependency graph of the current user
 environment:
 
 ```console
-$ nix-store --query --graph ~/.nix-profile | dot -Tps > graph.ps
+$ nix-store -q --graph ~/.nix-profile | dot -Tps > graph.ps
 $ gv graph.ps
 ```
 
@@ -220,7 +212,7 @@ Show every garbage collector root that points to a store path that
 depends on `svn`:
 
 ```console
-$ nix-store --query --roots $(which svn)
+$ nix-store -q --roots $(which svn)
 /nix/var/nix/profiles/default-81-link
 /nix/var/nix/profiles/default-82-link
 /home/eelco/.local/state/nix/profiles/profile-97-link

doc/manual/src/command-ref/nix-store/read-log.md

@@ -27,7 +27,7 @@ substitute, then the log is unavailable.
 # Example
 
 ```console
-$ nix-store --read-log $(which ktorrent)
+$ nix-store -l $(which ktorrent)
 building /nix/store/dhc73pvzpnzxhdgpimsd9sw39di66ph1-ktorrent-2.2.1
 unpacking sources
 unpacking source archive /nix/store/p8n1jpqs27mgkjw07pb5269717nzf5f8-ktorrent-2.2.1.tar.gz

doc/manual/src/command-ref/nix-store/realise.md

@@ -1,6 +1,6 @@
 # Name
 
-`nix-store --realise` - build or fetch store objects
+`nix-store --realise` - realise specified store paths
 
 # Synopsis
 
@@ -8,35 +8,33 @@
 
 # Description
 
+The operation `--realise` essentially “builds” the specified store
+paths. Realisation is a somewhat overloaded term:
 
-Each of *paths* is processed as follows:
+  - If the store path is a *derivation*, realisation ensures that the
+    output paths of the derivation are [valid] (i.e.,
+    the output path and its closure exist in the file system). This
+    can be done in several ways. First, it is possible that the
+    outputs are already valid, in which case we are done
+    immediately. Otherwise, there may be [substitutes]
+    that produce the outputs (e.g., by downloading them). Finally, the
+    outputs can be produced by running the build task described
+    by the derivation.
 
-- If the path leads to a [store derivation]:
-  1. If it is not [valid], substitute the store derivation file itself.
-  2. Realise its [output paths]:
-    - Try to fetch from [substituters] the [store objects] associated with the output paths in the store derivation's [closure].
-      - With [content-addressed derivations] (experimental): Determine the output paths to realise by querying content-addressed realisation entries in the [Nix database].
-    - For any store paths that cannot be substituted, produce the required store objects. This involves first realising all outputs of the derivation's dependencies and then running the derivation's [`builder`](@docroot@/language/derivations.md#attr-builder) executable. <!-- TODO: Link to build process page #8888 -->
-- Otherwise, and if the path is not already valid: Try to fetch the associated [store objects] in the path's [closure] from [substituters].
+  - If the store path is not a derivation, realisation ensures that the
+    specified path is valid (i.e., it and its closure exist in the file
+    system). If the path is already valid, we are done immediately.
+    Otherwise, the path and any missing paths in its closure may be
+    produced through substitutes. If there are no (successful)
+    substitutes, realisation fails.
 
-If no substitutes are available and no store derivation is given, realisation fails.
-
-[store paths]: @docroot@/glossary.md#gloss-store-path
 [valid]: @docroot@/glossary.md#gloss-validity
-[store derivation]: @docroot@/glossary.md#gloss-store-derivation
-[output paths]: @docroot@/glossary.md#gloss-output-path
-[store objects]: @docroot@/glossary.md#gloss-store-object
-[closure]: @docroot@/glossary.md#gloss-closure
-[substituters]: @docroot@/command-ref/conf-file.md#conf-substituters
-[content-addressed derivations]: @docroot@/contributing/experimental-features.md#xp-feature-ca-derivations
-[Nix database]: @docroot@/glossary.md#gloss-nix-database
+[substitutes]: @docroot@/glossary.md#gloss-substitute
 
-The resulting paths are printed on standard output.
-For non-derivation arguments, the argument itself is printed.
+The output path of each derivation is printed on standard output. (For
+non-derivations argument, the argument itself is printed.)
 
-{{#include ../status-build-failure.md}}
-
-# Options
+The following flags are available:
 
   - `--dry-run`\
     Print on standard error a description of what packages would be
@@ -56,6 +54,37 @@ For non-derivation arguments, the argument itself is printed.
     previous build, the new output path is left in
     `/nix/store/name.check.`
 
+Special exit codes:
+
+  - `100`\
+    Generic build failure, the builder process returned with a non-zero
+    exit code.
+
+  - `101`\
+    Build timeout, the build was aborted because it did not complete
+    within the specified `timeout`.
+
+  - `102`\
+    Hash mismatch, the build output was rejected because it does not
+    match the [`outputHash` attribute of the
+    derivation](@docroot@/language/advanced-attributes.md).
+
+  - `104`\
+    Not deterministic, the build succeeded in check mode but the
+    resulting output is not binary reproducible.
+
+With the `--keep-going` flag it's possible for multiple failures to
+occur, in this case the 1xx status codes are or combined using binary
+or.
+
+    1100100
+       ^^^^
+       |||`- timeout
+       ||`-- output hash mismatch
+       |`--- build failure
+       `---- not deterministic
+
+
 {{#include ./opt-common.md}}
 
 {{#include ../opt-common.md}}
@@ -67,8 +96,10 @@ For non-derivation arguments, the argument itself is printed.
 This operation is typically used to build [store derivation]s produced by
 [`nix-instantiate`](@docroot@/command-ref/nix-instantiate.md):
 
+[store derivation]: @docroot@/glossary.md#gloss-store-derivation
+
 ```console
-$ nix-store --realise $(nix-instantiate ./test.nix)
+$ nix-store -r $(nix-instantiate ./test.nix)
 /nix/store/31axcgrlbfsxzmfff1gyj1bf62hvkby2-aterm-2.3.1
 ```
 
@@ -77,7 +108,7 @@ This is essentially what [`nix-build`](@docroot@/command-ref/nix-build.md) does.
 To test whether a previously-built derivation is deterministic:
 
 ```console
-$ nix-build '<nixpkgs>' --attr hello --check -K
+$ nix-build '<nixpkgs>' -A hello --check -K
 ```
 
 Use [`nix-store --read-log`](./read-log.md) to show the stderr and stdout of a build:

doc/manual/src/command-ref/nix-store/verify-path.md

@@ -24,6 +24,6 @@ path has changed, and 1 otherwise.
 To verify the integrity of the `svn` command and all its dependencies:
 
 ```console
-$ nix-store --verify-path $(nix-store --query --requisites $(which svn))
+$ nix-store --verify-path $(nix-store -qR $(which svn))
 ```
 

doc/manual/src/command-ref/opt-common.md

@@ -2,204 +2,218 @@
 
 Most Nix commands accept the following command-line options:
 
-- <span id="opt-help">[`--help`](#opt-help)</span>
-
-  Prints out a summary of the command syntax and exits.
-
-- <span id="opt-version">[`--version`](#opt-version)</span>
-
-  Prints out the Nix version number on standard output and exits.
-
-- <span id="opt-verbose">[`--verbose`](#opt-verbose)</span> / `-v`
-
-  Increases the level of verbosity of diagnostic messages printed on standard error.
-  For each Nix operation, the information printed on standard output is well-defined;
-  any diagnostic information is printed on standard error, never on standard output.
-
-  This option may be specified repeatedly.
-  Currently, the following verbosity levels exist:
-
-  - `0` “Errors only”
-
-    Only print messages explaining why the Nix invocation failed.
-
-  - `1` “Informational”
-
-    Print *useful* messages about what Nix is doing.
-    This is the default.
-
-  - `2` “Talkative”
-
-    Print more informational messages.
-
-  - `3` “Chatty”
-
-    Print even more informational messages.
-
-  - `4` “Debug”
-   
-    Print debug information.
-
-  - `5` “Vomit”
-
-    Print vast amounts of debug information.
-
-- <span id="opt-quiet">[`--quiet`](#opt-quiet)</span>
-
-  Decreases the level of verbosity of diagnostic messages printed on standard error.
-  This is the inverse option to `-v` / `--verbose`.
-
-  This option may be specified repeatedly.
-  See the previous verbosity levels list.
-
-- <span id="opt-log-format">[`--log-format`](#opt-log-format)</span> *format*
-
-  This option can be used to change the output of the log format, with *format* being one of:
-
-  - `raw`
-
-    This is the raw format, as outputted by nix-build.
-
-  - `internal-json`
-
-    Outputs the logs in a structured manner.
-
-    > **Warning**
-    >
-    > While the schema itself is relatively stable, the format of
-    > the error-messages (namely of the `msg`-field) can change
-    > between releases.
-
-  - `bar`
-
-    Only display a progress bar during the builds.
-
-  - `bar-with-logs`
-
-    Display the raw logs, with the progress bar at the bottom.
-
-- <span id="opt-no-build-output">[`--no-build-output`](#opt-no-build-output)</span> / `-Q`
-
-  By default, output written by builders to standard output and standard error is echoed to the Nix command's standard error.
-  This option suppresses this behaviour.
-  Note that the builder's standard output and error are always written to a log file in `prefix/nix/var/log/nix`.
-
-- <span id="opt-max-jobs">[`--max-jobs`](#opt-max-jobs)</span> / `-j` *number*
-
-  Sets the maximum number of build jobs that Nix will perform in parallel to the specified number.
-  Specify `auto` to use the number of CPUs in the system.
-  The default is specified by the `max-jobs` configuration setting, which itself defaults to `1`.
-  A higher value is useful on SMP systems or to exploit I/O latency.
-
-  Setting it to `0` disallows building on the local machine, which is useful when you want builds to happen only on remote builders.
-
-- <span id="opt-cores">[`--cores`](#opt-cores)</span>
-
-  Sets the value of the `NIX_BUILD_CORES` environment variable in the invocation of builders.
-  Builders can use this variable at their discretion to control the maximum amount of parallelism.
-  For instance, in Nixpkgs, if the derivation attribute `enableParallelBuilding` is set to `true`, the builder passes the `-jN` flag to GNU Make.
-  It defaults to the value of the `cores` configuration setting, if set, or `1` otherwise.
-  The value `0` means that the builder should use all available CPU cores in the system.
-
-- <span id="opt-max-silent-time">[`--max-silent-time`](#opt-max-silent-time)</span>
-
-  Sets the maximum number of seconds that a builder can go without producing any data on standard output or standard error.
-  The default is specified by the `max-silent-time` configuration setting.
-  `0` means no time-out.
-
-- <span id="opt-timeout">[`--timeout`](#opt-timeout)</span>
-
-  Sets the maximum number of seconds that a builder can run.
-  The default is specified by the `timeout` configuration setting.
-  `0` means no timeout.
-
-- <span id="opt-keep-going">[`--keep-going`](#opt-keep-going)</span> / `-k`
-
-  Keep going in case of failed builds, to the greatest extent possible.
-  That is, if building an input of some derivation fails, Nix will still build the other inputs, but not the derivation itself.
-  Without this option, Nix stops if any build fails (except for builds of substitutes), possibly killing builds in progress (in case of parallel or distributed builds).
-
-- <span id="opt-keep-failed">[`--keep-failed`](#opt-keep-failed)</span> / `-K`
-
-  Specifies that in case of a build failure, the temporary directory (usually in `/tmp`) in which the build takes place should not be deleted.
-  The path of the build directory is printed as an informational message.
-
-- <span id="opt-fallback">[`--fallback`](#opt-fallback)</span>
-
-  Whenever Nix attempts to build a derivation for which substitutes are known for each output path, but realising the output paths through the substitutes fails, fall back on building the derivation.
-
-  The most common scenario in which this is useful is when we have registered substitutes in order to perform binary distribution from, say, a network repository.
-  If the repository is down, the realisation of the derivation will fail.
-  When this option is specified, Nix will build the derivation instead.
-  Thus, installation from binaries falls back on installation from source.
-  This option is not the default since it is generally not desirable for a transient failure in obtaining the substitutes to lead to a full build from source (with the related consumption of resources).
-
-- <span id="opt-readonly-mode">[`--readonly-mode`](#opt-readonly-mode)</span>
-
-  When this option is used, no attempt is made to open the Nix database.
-  Most Nix operations do need database access, so those operations will fail.
-
-- <span id="opt-arg">[`--arg`](#opt-arg)</span> *name* *value*
-
-  This option is accepted by `nix-env`, `nix-instantiate`, `nix-shell` and `nix-build`.
-  When evaluating Nix expressions, the expression evaluator will automatically try to call functions that it encounters.
-  It can automatically call functions for which every argument has a [default value](@docroot@/language/constructs.md#functions) (e.g., `{ argName ?  defaultValue }: ...`).
-
-  With `--arg`, you can also call functions that have arguments without a default value (or override a default value).
-  That is, if the evaluator encounters a function with an argument named *name*, it will call it with value *value*.
-
-  For instance, the top-level `default.nix` in Nixpkgs is actually a function:
-
-  ```nix
-  { # The system (e.g., `i686-linux') for which to build the packages.
-    system ? builtins.currentSystem
-    ...
-  }: ...
-  ```
-
-  So if you call this Nix expression (e.g., when you do `nix-env --install --attr pkgname`), the function will be called automatically using the value [`builtins.currentSystem`](@docroot@/language/builtins.md) for the `system` argument.
-  You can override this using `--arg`, e.g., `nix-env --install --attr pkgname --arg system \"i686-freebsd\"`.
-  (Note that since the argument is a Nix string literal, you have to escape the quotes.)
-
-- <span id="opt-argstr">[`--argstr`](#opt-argstr)</span> *name* *value*
-
-  This option is like `--arg`, only the value is not a Nix expression but a string.
-  So instead of `--arg system \"i686-linux\"` (the outer quotes are to keep the shell happy) you can say `--argstr system i686-linux`.
-
-- <span id="opt-attr">[`--attr`](#opt-attr)</span> / `-A` *attrPath*
-
-  Select an attribute from the top-level Nix expression being evaluated.
-  (`nix-env`, `nix-instantiate`, `nix-build` and `nix-shell` only.)
-  The *attribute path* *attrPath* is a sequence of attribute names separated by dots.
-  For instance, given a top-level Nix expression *e*, the attribute path `xorg.xorgserver` would cause the expression `e.xorg.xorgserver` to be used.
-  See [`nix-env --install`](@docroot@/command-ref/nix-env/install.md) for some concrete examples.
-
-  In addition to attribute names, you can also specify array indices.
-  For instance, the attribute path `foo.3.bar` selects the `bar`
-  attribute of the fourth element of the array in the `foo` attribute
-  of the top-level expression.
-
-- <span id="opt-expr">[`--expr`](#opt-expr)</span> / `-E`
-
-  Interpret the command line arguments as a list of Nix expressions to be parsed and evaluated, rather than as a list of file names of Nix expressions.
-  (`nix-instantiate`, `nix-build` and `nix-shell` only.)
-
-  For `nix-shell`, this option is commonly used to give you a shell in which you can build the packages returned by the expression.
-  If you want to get a shell which contain the *built* packages ready for use, give your expression to the `nix-shell --packages ` convenience flag instead.
-
-- <span id="opt-I">[`-I`](#opt-I)</span> *path*
-
-  Add an entry to the [Nix expression search path](@docroot@/command-ref/conf-file.md#conf-nix-path).
-  This option may be given multiple times.
-  Paths added through `-I` take precedence over [`NIX_PATH`](@docroot@/command-ref/env-common.md#env-NIX_PATH).
-
-- <span id="opt-option">[`--option`](#opt-option)</span> *name* *value*
-
-  Set the Nix configuration option *name* to *value*.
-  This overrides settings in the Nix configuration file (see nix.conf5).
-
-- <span id="opt-repair">[`--repair`](#opt-repair)</span>
-
-  Fix corrupted or missing store paths by redownloading or rebuilding them.
-  Note that this is slow because it requires computing a cryptographic hash of the contents of every path in the closure of the build.
-  Also note the warning under `nix-store --repair-path`.
+  - <span id="opt-help">[`--help`](#opt-help)</span>\
+    Prints out a summary of the command syntax and exits.
+
+  - <span id="opt-version">[`--version`](#opt-version)</span>\
+    Prints out the Nix version number on standard output and exits.
+
+  - <span id="opt-verbose">[`--verbose`](#opt-verbose)</span> / `-v`\
+    Increases the level of verbosity of diagnostic messages printed on
+    standard error. For each Nix operation, the information printed on
+    standard output is well-defined; any diagnostic information is
+    printed on standard error, never on standard output.
+
+    This option may be specified repeatedly. Currently, the following
+    verbosity levels exist:
+
+      - 0\
+        “Errors only”: only print messages explaining why the Nix
+        invocation failed.
+
+      - 1\
+        “Informational”: print *useful* messages about what Nix is
+        doing. This is the default.
+
+      - 2\
+        “Talkative”: print more informational messages.
+
+      - 3\
+        “Chatty”: print even more informational messages.
+
+      - 4\
+        “Debug”: print debug information.
+
+      - 5\
+        “Vomit”: print vast amounts of debug information.
+
+  - <span id="opt-quiet">[`--quiet`](#opt-quiet)</span>\
+    Decreases the level of verbosity of diagnostic messages printed on
+    standard error. This is the inverse option to `-v` / `--verbose`.
+
+    This option may be specified repeatedly. See the previous verbosity
+    levels list.
+
+  - <span id="opt-log-format">[`--log-format`](#opt-log-format)</span> *format*\
+    This option can be used to change the output of the log format, with
+    *format* being one of:
+
+      - raw\
+        This is the raw format, as outputted by nix-build.
+
+      - internal-json\
+        Outputs the logs in a structured manner.
+
+        > **Warning**
+        >
+        > While the schema itself is relatively stable, the format of
+        > the error-messages (namely of the `msg`-field) can change
+        > between releases.
+
+      - bar\
+        Only display a progress bar during the builds.
+
+      - bar-with-logs\
+        Display the raw logs, with the progress bar at the bottom.
+
+  - <span id="opt-no-build-output">[`--no-build-output`](#opt-no-build-output)</span> / `-Q`\
+    By default, output written by builders to standard output and
+    standard error is echoed to the Nix command's standard error. This
+    option suppresses this behaviour. Note that the builder's standard
+    output and error are always written to a log file in
+    `prefix/nix/var/log/nix`.
+
+  - <span id="opt-max-jobs">[`--max-jobs`](#opt-max-jobs)</span> / `-j` *number*\
+    Sets the maximum number of build jobs that Nix will perform in
+    parallel to the specified number. Specify `auto` to use the number
+    of CPUs in the system. The default is specified by the `max-jobs`
+    configuration setting, which itself defaults to `1`. A higher
+    value is useful on SMP systems or to exploit I/O latency.
+
+    Setting it to `0` disallows building on the local machine, which is
+    useful when you want builds to happen only on remote builders.
+
+  - <span id="opt-cores">[`--cores`](#opt-cores)</span>\
+    Sets the value of the `NIX_BUILD_CORES` environment variable in
+    the invocation of builders. Builders can use this variable at
+    their discretion to control the maximum amount of parallelism. For
+    instance, in Nixpkgs, if the derivation attribute
+    `enableParallelBuilding` is set to `true`, the builder passes the
+    `-jN` flag to GNU Make. It defaults to the value of the `cores`
+    configuration setting, if set, or `1` otherwise. The value `0`
+    means that the builder should use all available CPU cores in the
+    system.
+
+  - <span id="opt-max-silent-time">[`--max-silent-time`](#opt-max-silent-time)</span>\
+    Sets the maximum number of seconds that a builder can go without
+    producing any data on standard output or standard error. The
+    default is specified by the `max-silent-time` configuration
+    setting. `0` means no time-out.
+
+  - <span id="opt-timeout">[`--timeout`](#opt-timeout)</span>\
+    Sets the maximum number of seconds that a builder can run. The
+    default is specified by the `timeout` configuration setting. `0`
+    means no timeout.
+
+  - <span id="opt-keep-going">[`--keep-going`](#opt-keep-going)</span> / `-k`\
+    Keep going in case of failed builds, to the greatest extent
+    possible. That is, if building an input of some derivation fails,
+    Nix will still build the other inputs, but not the derivation
+    itself. Without this option, Nix stops if any build fails (except
+    for builds of substitutes), possibly killing builds in progress (in
+    case of parallel or distributed builds).
+
+  - <span id="opt-keep-failed">[`--keep-failed`](#opt-keep-failed)</span> / `-K`\
+    Specifies that in case of a build failure, the temporary directory
+    (usually in `/tmp`) in which the build takes place should not be
+    deleted. The path of the build directory is printed as an
+    informational message.
+
+  - <span id="opt-fallback">[`--fallback`](#opt-fallback)</span>\
+    Whenever Nix attempts to build a derivation for which substitutes
+    are known for each output path, but realising the output paths
+    through the substitutes fails, fall back on building the derivation.
+
+    The most common scenario in which this is useful is when we have
+    registered substitutes in order to perform binary distribution from,
+    say, a network repository. If the repository is down, the
+    realisation of the derivation will fail. When this option is
+    specified, Nix will build the derivation instead. Thus, installation
+    from binaries falls back on installation from source. This option is
+    not the default since it is generally not desirable for a transient
+    failure in obtaining the substitutes to lead to a full build from
+    source (with the related consumption of resources).
+
+  - <span id="opt-readonly-mode">[`--readonly-mode`](#opt-readonly-mode)</span>\
+    When this option is used, no attempt is made to open the Nix
+    database. Most Nix operations do need database access, so those
+    operations will fail.
+
+  - <span id="opt-arg">[`--arg`](#opt-arg)</span> *name* *value*\
+    This option is accepted by `nix-env`, `nix-instantiate`,
+    `nix-shell` and `nix-build`. When evaluating Nix expressions, the
+    expression evaluator will automatically try to call functions that
+    it encounters. It can automatically call functions for which every
+    argument has a [default
+    value](@docroot@/language/constructs.md#functions) (e.g.,
+    `{ argName ?  defaultValue }: ...`). With `--arg`, you can also
+    call functions that have arguments without a default value (or
+    override a default value). That is, if the evaluator encounters a
+    function with an argument named *name*, it will call it with value
+    *value*.
+
+    For instance, the top-level `default.nix` in Nixpkgs is actually a
+    function:
+
+    ```nix
+    { # The system (e.g., `i686-linux') for which to build the packages.
+      system ? builtins.currentSystem
+      ...
+    }: ...
+    ```
+
+    So if you call this Nix expression (e.g., when you do `nix-env -iA
+    pkgname`), the function will be called automatically using the
+    value [`builtins.currentSystem`](@docroot@/language/builtins.md) for
+    the `system` argument. You can override this using `--arg`, e.g.,
+    `nix-env -iA pkgname --arg system \"i686-freebsd\"`. (Note that
+    since the argument is a Nix string literal, you have to escape the
+    quotes.)
+
+  - <span id="opt-argstr">[`--argstr`](#opt-argstr)</span> *name* *value*\
+    This option is like `--arg`, only the value is not a Nix
+    expression but a string. So instead of `--arg system
+    \"i686-linux\"` (the outer quotes are to keep the shell happy) you
+    can say `--argstr system i686-linux`.
+
+  - <span id="opt-attr">[`--attr`](#opt-attr)</span> / `-A` *attrPath*\
+    Select an attribute from the top-level Nix expression being
+    evaluated. (`nix-env`, `nix-instantiate`, `nix-build` and
+    `nix-shell` only.) The *attribute path* *attrPath* is a sequence
+    of attribute names separated by dots. For instance, given a
+    top-level Nix expression *e*, the attribute path `xorg.xorgserver`
+    would cause the expression `e.xorg.xorgserver` to be used. See
+    [`nix-env --install`](@docroot@/command-ref/nix-env/install.md) for some
+    concrete examples.
+
+    In addition to attribute names, you can also specify array indices.
+    For instance, the attribute path `foo.3.bar` selects the `bar`
+    attribute of the fourth element of the array in the `foo` attribute
+    of the top-level expression.
+
+  - <span id="opt-expr">[`--expr`](#opt-expr)</span> / `-E`\
+    Interpret the command line arguments as a list of Nix expressions to
+    be parsed and evaluated, rather than as a list of file names of Nix
+    expressions. (`nix-instantiate`, `nix-build` and `nix-shell` only.)
+
+    For `nix-shell`, this option is commonly used to give you a shell in
+    which you can build the packages returned by the expression. If you
+    want to get a shell which contain the *built* packages ready for
+    use, give your expression to the `nix-shell -p` convenience flag
+    instead.
+
+  - <span id="opt-I">[`-I`](#opt-I)</span> *path*\
+    Add a path to the Nix expression search path. This option may be
+    given multiple times. See the `NIX_PATH` environment variable for
+    information on the semantics of the Nix search path. Paths added
+    through `-I` take precedence over `NIX_PATH`.
+
+  - <span id="opt-option">[`--option`](#opt-option)</span> *name* *value*\
+    Set the Nix configuration option *name* to *value*. This overrides
+    settings in the Nix configuration file (see nix.conf5).
+
+  - <span id="opt-repair">[`--repair`](#opt-repair)</span>\
+    Fix corrupted or missing store paths by redownloading or rebuilding
+    them. Note that this is slow because it requires computing a
+    cryptographic hash of the contents of every path in the closure of
+    the build. Also note the warning under `nix-store --repair-path`.

doc/manual/src/command-ref/status-build-failure.md

@@ -1,34 +0,0 @@
-# Special exit codes for build failure
-
-1xx status codes are used when requested builds failed.
-The following codes are in use:
-
-- `100` Generic build failure
-
-  The builder process returned with a non-zero exit code.
-
-- `101` Build timeout
-
-  The build was aborted because it did not complete within the specified `timeout`.
-
-- `102` Hash mismatch
-
-  The build output was rejected because it does not match the
-  [`outputHash` attribute of the derivation](@docroot@/language/advanced-attributes.md).
-
-- `104` Not deterministic
-
-  The build succeeded in check mode but the resulting output is not binary reproducible.
-
-With the `--keep-going` flag it's possible for multiple failures to occur.
-In this case the 1xx status codes are or combined using
-[bitwise OR](https://en.wikipedia.org/wiki/Bitwise_operation#OR).
-
-```
-0b1100100
-     ^^^^
-     |||`- timeout
-     ||`-- output hash mismatch
-     |`--- build failure
-     `---- not deterministic
-```

doc/manual/src/contributing/cxx.md

@@ -1,28 +0,0 @@
-# C++ style guide
-
-Some miscellaneous notes on how we write C++.
-Formatting we hope to eventually normalize automatically, so this section is free to just discuss higher-level concerns.
-
-## The `*-impl.hh` pattern
-
-Let's start with some background info first.
-Headers, are supposed to contain declarations, not definitions.
-This allows us to change a definition without changing the declaration, and have a very small rebuild during development.
-Templates, however, need to be specialized to use-sites.
-Absent fancier techniques, templates require that the definition, not just mere declaration, must be available at use-sites in order to make that specialization on the fly as part of compiling those use-sites.
-Making definitions available like that means putting them in headers, but that is unfortunately means we get all the extra rebuilds we want to avoid by just putting declarations there as described above.
-
-The `*-impl.hh` pattern is a ham-fisted partial solution to this problem.
-It constitutes:
-
-- Declaring items only in the main `foo.hh`, including templates.
-
-- Putting template definitions in a companion `foo-impl.hh` header.
-
-Most C++ developers would accompany this by having `foo.hh` include `foo-impl.hh`, to ensure any file getting the template declarations also got the template definitions.
-But we've found not doing this has some benefits and fewer than imagined downsides.
-The fact remains that headers are rarely as minimal as they could be;
-there is often code that needs declarations from the headers but not the templates within them.
-With our pattern where `foo.hh` doesn't include `foo-impl.hh`, that means they can just include `foo.hh`
-Code that needs both just includes `foo.hh` and `foo-impl.hh`.
-This does make linking error possible where something forgets to include `foo-impl.hh` that needs it, but those are build-time only as easy to fix.

doc/manual/src/contributing/hacking.md

@@ -12,15 +12,14 @@ The following instructions assume you already have some version of Nix installed
 
 [installation instructions]: ../installation/installation.md
 
-## Building Nix with flakes
+## Nix with flakes
 
-This section assumes you are using Nix with the [`flakes`] and [`nix-command`] experimental features enabled.
-See the [Building Nix](#building-nix) section for equivalent instructions using stable Nix interfaces.
+This section assumes you are using Nix with [flakes] enabled. See the [next section](#classic-nix) for equivalent instructions which don't require flakes.
 
-[`flakes`]: @docroot@/contributing/experimental-features.md#xp-feature-flakes
-[`nix-command`]: @docroot@/contributing/experimental-features.md#xp-nix-command
+[flakes]: ../command-ref/new-cli/nix3-flake.md#description
 
-To build all dependencies and start a shell in which all environment variables are set up so that those dependencies can be found:
+To build all dependencies and start a shell in which all environment
+variables are set up so that those dependencies can be found:
 
 ```console
 $ nix develop
@@ -56,17 +55,20 @@ To install it in `$(pwd)/outputs` and test it:
 nix (Nix) 2.12
 ```
 
-To build a release version of Nix for the current operating system and CPU architecture:
+To build a release version of Nix:
 
 ```console
 $ nix build
 ```
 
-You can also build Nix for one of the [supported platforms](#platforms).
+You can also build Nix for one of the [supported target platforms](#target-platforms).
 
-## Building Nix
+## Classic Nix
 
-To build all dependencies and start a shell in which all environment variables are set up so that those dependencies can be found:
+This section is for Nix without [flakes].
+
+To build all dependencies and start a shell in which all environment
+variables are set up so that those dependencies can be found:
 
 ```console
 $ nix-shell
@@ -75,7 +77,7 @@ $ nix-shell
 To get a shell with one of the other [supported compilation environments](#compilation-environments):
 
 ```console
-$ nix-shell --attr devShells.x86_64-linux.native-clang11StdenvPackages
+$ nix-shell -A devShells.x86_64-linux.native-clang11StdenvPackages
 ```
 
 > **Note**
@@ -100,82 +102,51 @@ To install it in `$(pwd)/outputs` and test it:
 nix (Nix) 2.12
 ```
 
-To build a release version of Nix for the current operating system and CPU architecture:
+To build Nix for the current operating system and CPU architecture use
 
 ```console
 $ nix-build
 ```
 
-You can also build Nix for one of the [supported platforms](#platforms).
+You can also build Nix for one of the [supported target platforms](#target-platforms).
 
 ## Platforms
 
-Nix can be built for various platforms, as specified in [`flake.nix`]:
+As specified in [`flake.nix`], Nix can be built for various platforms:
+
+- `aarch64-linux`
+- `i686-linux`
+- `x86_64-darwin`
+- `x86_64-linux`
 
 [`flake.nix`]: https://github.com/nixos/nix/blob/master/flake.nix
 
-- `x86_64-linux`
-- `x86_64-darwin`
-- `i686-linux`
-- `aarch64-linux`
-- `aarch64-darwin`
-- `armv6l-linux`
-- `armv7l-linux`
-
 In order to build Nix for a different platform than the one you're currently
-on, you need a way for your current Nix installation to build code for that
-platform. Common solutions include [remote builders] and [binary format emulation]
+on, you need to have some way for your system Nix to build code for that
+platform. Common solutions include [remote builders] and [binfmt emulation]
 (only supported on NixOS).
 
 [remote builders]: ../advanced-topics/distributed-builds.md
-[binary format emulation]: https://nixos.org/manual/nixos/stable/options.html#opt-boot.binfmt.emulatedSystems
+[binfmt emulation]: https://nixos.org/manual/nixos/stable/options.html#opt-boot.binfmt.emulatedSystems
 
-Given such a setup, executing the build only requires selecting the respective attribute.
-For example, to compile for `aarch64-linux`:
-
-```console
-$ nix-build --attr packages.aarch64-linux.default
-```
-
-or for Nix with the [`flakes`] and [`nix-command`] experimental features enabled:
+These solutions let Nix perform builds as if you're on the native platform, so
+executing the build is as simple as
 
 ```console
 $ nix build .#packages.aarch64-linux.default
 ```
 
-Cross-compiled builds are available for ARMv6 (`armv6l-linux`) and ARMv7 (`armv7l-linux`).
-Add more [system types](#system-type) to `crossSystems` in `flake.nix` to bootstrap Nix on unsupported platforms.
+for flake-enabled Nix, or
 
-## System type
-
-Nix uses a string with he following format to identify the *system type* or *platform* it runs on:
-
-```
-<cpu>-<os>[-<abi>]
+```console
+$ nix-build -A packages.aarch64-linux.default
 ```
 
-It is set when Nix is compiled for the given system, and based on the output of [`config.guess`](https://github.com/nixos/nix/blob/master/config/config.guess) ([upstream](https://git.savannah.gnu.org/cgit/config.git/tree/config.guess)):
+for classic Nix.
 
-```
-<cpu>-<vendor>-<os>[<version>][-<abi>]
-```
+You can use any of the other supported platforms in place of `aarch64-linux`.
 
-When Nix is built such that `./configure` is passed any of the `--host`, `--build`, `--target` options, the value is based on the output of [`config.sub`](https://github.com/nixos/nix/blob/master/config/config.sub) ([upstream](https://git.savannah.gnu.org/cgit/config.git/tree/config.sub)):
-
-```
-<cpu>-<vendor>[-<kernel>]-<os>
-```
-
-For historic reasons and backward-compatibility, some CPU and OS identifiers are translated from the GNU Autotools naming convention in [`configure.ac`](https://github.com/nixos/nix/blob/master/configure.ac) as follows:
-
-| `config.guess`             | Nix                 |
-|----------------------------|---------------------|
-| `amd64`                    | `x86_64`            |
-| `i*86`                     | `i686`              |
-| `arm6`                     | `arm6l`             |
-| `arm7`                     | `arm7l`             |
-| `linux-gnu*`               | `linux`             |
-| `linux-musl*`              | `linux`             |
+Cross-compiled builds are available for ARMv6 and ARMv7, and Nix on unsupported platforms can be bootstrapped by adding more `crossSystems` in `flake.nix`.
 
 ## Compilation environments
 
@@ -195,7 +166,7 @@ $ nix build .#nix-ccacheStdenv
 for flake-enabled Nix, or
 
 ```console
-$ nix-build --attr nix-ccacheStdenv
+$ nix-build -A nix-ccacheStdenv
 ```
 
 for classic Nix.
@@ -221,6 +192,171 @@ Configure your editor to use the `clangd` from the shell, either by running it i
 > Some other editors (e.g. Emacs, Vim) need a plugin to support LSP servers in general (e.g. [lsp-mode](https://github.com/emacs-lsp/lsp-mode) for Emacs and [vim-lsp](https://github.com/prabirshrestha/vim-lsp) for vim).
 > Editor-specific setup is typically opinionated, so we will not cover it here in more detail.
 
+## Running tests
+
+### Unit-tests
+
+The unit-tests for each Nix library (`libexpr`, `libstore`, etc..) are defined
+under `src/{library_name}/tests` using the
+[googletest](https://google.github.io/googletest/) and
+[rapidcheck](https://github.com/emil-e/rapidcheck) frameworks.
+
+You can run the whole testsuite with `make check`, or the tests for a specific component with `make libfoo-tests_RUN`. Finer-grained filtering is also possible using the [--gtest_filter](https://google.github.io/googletest/advanced.html#running-a-subset-of-the-tests) command-line option.
+
+### Functional tests
+
+The functional tests reside under the `tests` directory and are listed in `tests/local.mk`.
+Each test is a bash script.
+
+The whole test suite can be run with:
+
+```shell-session
+$ make install && make installcheck
+ran test tests/foo.sh... [PASS]
+ran test tests/bar.sh... [PASS]
+...
+```
+
+Individual tests can be run with `make`:
+
+```shell-session
+$ make tests/${testName}.sh.test
+ran test tests/${testName}.sh... [PASS]
+```
+
+or without `make`:
+
+```shell-session
+$ ./mk/run-test.sh tests/${testName}.sh
+ran test tests/${testName}.sh... [PASS]
+```
+
+To see the complete output, one can also run:
+
+```shell-session
+$ ./mk/debug-test.sh tests/${testName}.sh
++ foo
+output from foo
++ bar
+output from bar
+...
+```
+
+The test script will then be traced with `set -x` and the output displayed as it happens, regardless of whether the test succeeds or fails.
+
+#### Debugging failing functional tests
+
+When a functional test fails, it usually does so somewhere in the middle of the script.
+
+To figure out what's wrong, it is convenient to run the test regularly up to the failing `nix` command, and then run that command with a debugger like GDB.
+
+For example, if the script looks like:
+
+```bash
+foo
+nix blah blub
+bar
+```
+edit it like so:
+
+```diff
+ foo
+-nix blah blub
++gdb --args nix blah blub
+ bar
+```
+
+Then, running the test with `./mk/debug-test.sh` will drop you into GDB once the script reaches that point:
+
+```shell-session
+$ ./mk/debug-test.sh tests/${testName}.sh
+...
++ gdb blash blub
+GNU gdb (GDB) 12.1
+...
+(gdb)
+```
+
+One can debug the Nix invocation in all the usual ways.
+For example, enter `run` to start the Nix invocation.
+
+### Integration tests
+
+The integration tests are defined in the Nix flake under the `hydraJobs.tests` attribute.
+These tests include everything that needs to interact with external services or run Nix in a non-trivial distributed setup.
+Because these tests are expensive and require more than what the standard github-actions setup provides, they only run on the master branch (on <https://hydra.nixos.org/jobset/nix/master>).
+
+You can run them manually with `nix build .#hydraJobs.tests.{testName}` or `nix-build -A hydraJobs.tests.{testName}`
+
+### Installer tests
+
+After a one-time setup, the Nix repository's GitHub Actions continuous integration (CI) workflow can test the installer each time you push to a branch.
+
+Creating a Cachix cache for your installer tests and adding its authorization token to GitHub enables [two installer-specific jobs in the CI workflow](https://github.com/NixOS/nix/blob/88a45d6149c0e304f6eb2efcc2d7a4d0d569f8af/.github/workflows/ci.yml#L50-L91):
+
+- The `installer` job generates installers for the platforms below and uploads them to your Cachix cache:
+  - `x86_64-linux`
+  - `armv6l-linux`
+  - `armv7l-linux`
+  - `x86_64-darwin`
+
+- The `installer_test` job (which runs on `ubuntu-latest` and `macos-latest`) will try to install Nix with the cached installer and run a trivial Nix command.
+
+#### One-time setup
+
+1. Have a GitHub account with a fork of the [Nix repository](https://github.com/NixOS/nix).
+2. At cachix.org:
+    - Create or log in to an account.
+    - Create a Cachix cache using the format `<github-username>-nix-install-tests`.
+    - Navigate to the new cache > Settings > Auth Tokens.
+    - Generate a new Cachix auth token and copy the generated value.
+3. At github.com:
+    - Navigate to your Nix fork > Settings > Secrets > Actions > New repository secret.
+    - Name the secret `CACHIX_AUTH_TOKEN`.
+    - Paste the copied value of the Cachix cache auth token.
+
+#### Using the CI-generated installer for manual testing
+
+After the CI run completes, you can check the output to extract the installer URL:
+1. Click into the detailed view of the CI run.
+2. Click into any `installer_test` run (the URL you're here to extract will be the same in all of them).
+3. Click into the `Run cachix/install-nix-action@v...` step and click the detail triangle next to the first log line (it will also be `Run cachix/install-nix-action@v...`)
+4. Copy the value of `install_url`
+5. To generate an install command, plug this `install_url` and your GitHub username into this template:
+
+    ```console
+    curl -L <install_url> | sh -s -- --tarball-url-prefix https://<github-username>-nix-install-tests.cachix.org/serve
+    ```
+
+<!-- #### Manually generating test installers
+
+There's obviously a manual way to do this, and it's still the only way for
+platforms that lack GA runners.
+
+I did do this back in Fall 2020 (before the GA approach encouraged here). I'll
+sketch what I recall in case it encourages someone to fill in detail, but: I
+didn't know what I was doing at the time and had to fumble/ask around a lot--
+so I don't want to uphold any of it as "right". It may have been dumb or
+the _hard_ way from the getgo. Fundamentals may have changed since.
+
+Here's the build command I used to do this on and for x86_64-darwin:
+nix build --out-link /tmp/foo ".#checks.x86_64-darwin.binaryTarball"
+
+I used the stable out-link to make it easier to script the next steps:
+link=$(readlink /tmp/foo)
+cp $link/*-darwin.tar.xz ~/somewheres
+
+I've lost the last steps and am just going from memory:
+
+From here, I think I had to extract and modify the `install` script to point
+it at this tarball (which I scped to my own site, but it might make more sense
+to just share them locally). I extracted this script once and then just
+search/replaced in it for each new build.
+
+The installer now supports a `--tarball-url-prefix` flag which _may_ have
+solved this need?
+-->
+
 ### Checking links in the manual
 
 The build checks for broken internal links.
@@ -242,7 +378,7 @@ rm $(git ls-files doc/manual/ -o | grep -F '.md') && rmdir doc/manual/src/comman
 [`mdbook-linkcheck`] does not implement checking [URI fragments] yet.
 
 [`mdbook-linkcheck`]: https://github.com/Michael-F-Bryan/mdbook-linkcheck
-[URI fragments]: https://en.wikipedia.org/wiki/URI_fragment
+[URI fragments]: https://en.m.wikipedia.org/wiki/URI_fragment
 
 #### `@docroot@` variable
 

doc/manual/src/contributing/testing.md

@@ -1,236 +0,0 @@
-# Running tests
-
-## Unit-tests
-
-The unit-tests for each Nix library (`libexpr`, `libstore`, etc..) are defined
-under `tests/unit/{library_name}/tests` using the
-[googletest](https://google.github.io/googletest/) and
-[rapidcheck](https://github.com/emil-e/rapidcheck) frameworks.
-
-You can run the whole testsuite with `make check`, or the tests for a specific component with `make libfoo-tests_RUN`.
-Finer-grained filtering is also possible using the [--gtest_filter](https://google.github.io/googletest/advanced.html#running-a-subset-of-the-tests) command-line option, or the `GTEST_FILTER` environment variable.
-
-### Unit test support libraries
-
-There are headers and code which are not just used to test the library in question, but also downstream libraries.
-For example, we do [property testing] with the [rapidcheck] library.
-This requires writing `Arbitrary` "instances", which are used to describe how to generate values of a given type for the sake of running property tests.
-Because types contain other types, `Arbitrary` "instances" for some type are not just useful for testing that type, but also any other type that contains it.
-Downstream types frequently contain upstream types, so it is very important that we share arbitrary instances so that downstream libraries' property tests can also use them.
-
-It is important that these testing libraries don't contain any actual tests themselves.
-On some platforms they would be run as part of every test executable that uses them, which is redundant.
-On other platforms they wouldn't be run at all.
-
-## Functional tests
-
-The functional tests reside under the `tests/functional` directory and are listed in `tests/functional/local.mk`.
-Each test is a bash script.
-
-### Running the whole test suite
-
-The whole test suite can be run with:
-
-```shell-session
-$ make install && make installcheck
-ran test tests/functional/foo.sh... [PASS]
-ran test tests/functional/bar.sh... [PASS]
-...
-```
-
-### Grouping tests
-
-Sometimes it is useful to group related tests so they can be easily run together without running the entire test suite.
-Each test group is in a subdirectory of `tests`.
-For example, `tests/functional/ca/local.mk` defines a `ca` test group for content-addressed derivation outputs.
-
-That test group can be run like this:
-
-```shell-session
-$ make ca.test-group -j50
-ran test tests/functional/ca/nix-run.sh... [PASS]
-ran test tests/functional/ca/import-derivation.sh... [PASS]
-...
-```
-
-The test group is defined in Make like this:
-```makefile
-$(test-group-name)-tests := \
-  $(d)/test0.sh \
-  $(d)/test1.sh \
-  ...
-
-install-tests-groups += $(test-group-name)
-```
-
-### Running individual tests
-
-Individual tests can be run with `make`:
-
-```shell-session
-$ make tests/functional/${testName}.sh.test
-ran test tests/functional/${testName}.sh... [PASS]
-```
-
-or without `make`:
-
-```shell-session
-$ ./mk/run-test.sh tests/functional/${testName}.sh
-ran test tests/functional/${testName}.sh... [PASS]
-```
-
-To see the complete output, one can also run:
-
-```shell-session
-$ ./mk/debug-test.sh tests/functional/${testName}.sh
-+ foo
-output from foo
-+ bar
-output from bar
-...
-```
-
-The test script will then be traced with `set -x` and the output displayed as it happens, regardless of whether the test succeeds or fails.
-
-### Debugging failing functional tests
-
-When a functional test fails, it usually does so somewhere in the middle of the script.
-
-To figure out what's wrong, it is convenient to run the test regularly up to the failing `nix` command, and then run that command with a debugger like GDB.
-
-For example, if the script looks like:
-
-```bash
-foo
-nix blah blub
-bar
-```
-edit it like so:
-
-```diff
- foo
--nix blah blub
-+gdb --args nix blah blub
- bar
-```
-
-Then, running the test with `./mk/debug-test.sh` will drop you into GDB once the script reaches that point:
-
-```shell-session
-$ ./mk/debug-test.sh tests/functional/${testName}.sh
-...
-+ gdb blash blub
-GNU gdb (GDB) 12.1
-...
-(gdb)
-```
-
-One can debug the Nix invocation in all the usual ways.
-For example, enter `run` to start the Nix invocation.
-
-### Characterization testing
-
-Occasionally, Nix utilizes a technique called [Characterization Testing](https://en.wikipedia.org/wiki/Characterization_test) as part of the functional tests.
-This technique is to include the exact output/behavior of a former version of Nix in a test in order to check that Nix continues to produce the same behavior going forward.
-
-For example, this technique is used for the language tests, to check both the printed final value if evaluation was successful, and any errors and warnings encountered.
-
-It is frequently useful to regenerate the expected output.
-To do that, rerun the failed test(s) with `_NIX_TEST_ACCEPT=1`.
-For example:
-```bash
-_NIX_TEST_ACCEPT=1 make tests/functional/lang.sh.test
-```
-
-An interesting situation to document is the case when these tests are "overfitted".
-The language tests are, again, an example of this.
-The expected successful output of evaluation is supposed to be highly stable – we do not intend to make breaking changes to (the stable parts of) the Nix language.
-However, the errors and warnings during evaluation (successful or not) are not stable in this way.
-We are free to change how they are displayed at any time.
-
-It may be surprising that we would test non-normative behavior like diagnostic outputs.
-Diagnostic outputs are indeed not a stable interface, but they still are important to users.
-By recording the expected output, the test suite guards against accidental changes, and ensure the *result* (not just the code that implements it) of the diagnostic code paths are under code review.
-Regressions are caught, and improvements always show up in code review.
-
-To ensure that characterization testing doesn't make it harder to intentionally change these interfaces, there always must be an easy way to regenerate the expected output, as we do with `_NIX_TEST_ACCEPT=1`.
-
-## Integration tests
-
-The integration tests are defined in the Nix flake under the `hydraJobs.tests` attribute.
-These tests include everything that needs to interact with external services or run Nix in a non-trivial distributed setup.
-Because these tests are expensive and require more than what the standard github-actions setup provides, they only run on the master branch (on <https://hydra.nixos.org/jobset/nix/master>).
-
-You can run them manually with `nix build .#hydraJobs.tests.{testName}` or `nix-build -A hydraJobs.tests.{testName}`
-
-## Installer tests
-
-After a one-time setup, the Nix repository's GitHub Actions continuous integration (CI) workflow can test the installer each time you push to a branch.
-
-Creating a Cachix cache for your installer tests and adding its authorization token to GitHub enables [two installer-specific jobs in the CI workflow](https://github.com/NixOS/nix/blob/88a45d6149c0e304f6eb2efcc2d7a4d0d569f8af/.github/workflows/ci.yml#L50-L91):
-
-- The `installer` job generates installers for the platforms below and uploads them to your Cachix cache:
-  - `x86_64-linux`
-  - `armv6l-linux`
-  - `armv7l-linux`
-  - `x86_64-darwin`
-
-- The `installer_test` job (which runs on `ubuntu-latest` and `macos-latest`) will try to install Nix with the cached installer and run a trivial Nix command.
-
-### One-time setup
-
-1. Have a GitHub account with a fork of the [Nix repository](https://github.com/NixOS/nix).
-2. At cachix.org:
-    - Create or log in to an account.
-    - Create a Cachix cache using the format `<github-username>-nix-install-tests`.
-    - Navigate to the new cache > Settings > Auth Tokens.
-    - Generate a new Cachix auth token and copy the generated value.
-3. At github.com:
-    - Navigate to your Nix fork > Settings > Secrets > Actions > New repository secret.
-    - Name the secret `CACHIX_AUTH_TOKEN`.
-    - Paste the copied value of the Cachix cache auth token.
-
-## Working on documentation
-
-### Using the CI-generated installer for manual testing
-
-After the CI run completes, you can check the output to extract the installer URL:
-1. Click into the detailed view of the CI run.
-2. Click into any `installer_test` run (the URL you're here to extract will be the same in all of them).
-3. Click into the `Run cachix/install-nix-action@v...` step and click the detail triangle next to the first log line (it will also be `Run cachix/install-nix-action@v...`)
-4. Copy the value of `install_url`
-5. To generate an install command, plug this `install_url` and your GitHub username into this template:
-
-    ```console
-    curl -L <install_url> | sh -s -- --tarball-url-prefix https://<github-username>-nix-install-tests.cachix.org/serve
-    ```
-
-<!-- #### Manually generating test installers
-
-There's obviously a manual way to do this, and it's still the only way for
-platforms that lack GA runners.
-
-I did do this back in Fall 2020 (before the GA approach encouraged here). I'll
-sketch what I recall in case it encourages someone to fill in detail, but: I
-didn't know what I was doing at the time and had to fumble/ask around a lot--
-so I don't want to uphold any of it as "right". It may have been dumb or
-the _hard_ way from the getgo. Fundamentals may have changed since.
-
-Here's the build command I used to do this on and for x86_64-darwin:
-nix build --out-link /tmp/foo ".#checks.x86_64-darwin.binaryTarball"
-
-I used the stable out-link to make it easier to script the next steps:
-link=$(readlink /tmp/foo)
-cp $link/*-darwin.tar.xz ~/somewheres
-
-I've lost the last steps and am just going from memory:
-
-From here, I think I had to extract and modify the `install` script to point
-it at this tarball (which I scped to my own site, but it might make more sense
-to just share them locally). I extracted this script once and then just
-search/replaced in it for each new build.
-
-The installer now supports a `--tarball-url-prefix` flag which _may_ have
-solved this need?
--->
-

doc/manual/src/favicon.svg

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doc/manual/src/glossary.md

@@ -1,275 +1,227 @@
 # Glossary
 
-- [derivation]{#gloss-derivation}
+  - [derivation]{#gloss-derivation}\
+    A description of a build task. The result of a derivation is a
+    store object. Derivations are typically specified in Nix expressions
+    using the [`derivation` primitive](./language/derivations.md). These are
+    translated into low-level *store derivations* (implicitly by
+    `nix-env` and `nix-build`, or explicitly by `nix-instantiate`).
 
-  A description of a build task. The result of a derivation is a
-  store object. Derivations are typically specified in Nix expressions
-  using the [`derivation` primitive](./language/derivations.md). These are
-  translated into low-level *store derivations* (implicitly by
-  `nix-env` and `nix-build`, or explicitly by `nix-instantiate`).
+    [derivation]: #gloss-derivation
 
-  [derivation]: #gloss-derivation
+  - [store derivation]{#gloss-store-derivation}\
+    A [derivation] represented as a `.drv` file in the [store].
+    It has a [store path], like any [store object].
 
-- [store derivation]{#gloss-store-derivation}
+    Example: `/nix/store/g946hcz4c8mdvq2g8vxx42z51qb71rvp-git-2.38.1.drv`
 
-  A [derivation] represented as a `.drv` file in the [store].
-  It has a [store path], like any [store object].
+    See [`nix derivation show`](./command-ref/new-cli/nix3-derivation-show.md) (experimental) for displaying the contents of store derivations.
 
-  Example: `/nix/store/g946hcz4c8mdvq2g8vxx42z51qb71rvp-git-2.38.1.drv`
+    [store derivation]: #gloss-store-derivation
 
-  See [`nix derivation show`](./command-ref/new-cli/nix3-derivation-show.md) (experimental) for displaying the contents of store derivations.
+  - [instantiate]{#gloss-instantiate}, instantiation\
+    Translate a [derivation] into a [store derivation].
 
-  [store derivation]: #gloss-store-derivation
+    See [`nix-instantiate`](./command-ref/nix-instantiate.md).
 
-- [instantiate]{#gloss-instantiate}, instantiation
+    [instantiate]: #gloss-instantiate
 
-  Translate a [derivation] into a [store derivation].
+  - [realise]{#gloss-realise}, realisation\
+    Ensure a [store path] is [valid][validity].
 
-  See [`nix-instantiate`](./command-ref/nix-instantiate.md).
+    This means either running the `builder` executable as specified in the corresponding [derivation] or fetching a pre-built [store object] from a [substituter].
 
-  [instantiate]: #gloss-instantiate
+    See [`nix-build`](./command-ref/nix-build.md) and [`nix-store --realise`](@docroot@/command-ref/nix-store/realise.md).
 
-- [realise]{#gloss-realise}, realisation
+    See [`nix build`](./command-ref/new-cli/nix3-build.md) (experimental).
 
-  Ensure a [store path] is [valid][validity].
+    [realise]: #gloss-realise
 
-  This means either running the [`builder`](@docroot@/language/derivations.md#attr-builder) executable as specified in the corresponding [derivation], or fetching a pre-built [store object] from a [substituter], or delegating to a [remote builder](@docroot@/advanced-topics/distributed-builds.html) and retrieving the outputs. <!-- TODO: link [running] to build process page, #8888 -->
+  - [content-addressed derivation]{#gloss-content-addressed-derivation}\
+    A derivation which has the
+    [`__contentAddressed`](./language/advanced-attributes.md#adv-attr-__contentAddressed)
+    attribute set to `true`.
 
-  See [`nix-build`](./command-ref/nix-build.md) and [`nix-store --realise`](@docroot@/command-ref/nix-store/realise.md).
+  - [fixed-output derivation]{#gloss-fixed-output-derivation}\
+    A derivation which includes the
+    [`outputHash`](./language/advanced-attributes.md#adv-attr-outputHash) attribute.
 
-  See [`nix build`](./command-ref/new-cli/nix3-build.md) (experimental).
+  - [store]{#gloss-store}\
+    The location in the file system where store objects live. Typically
+    `/nix/store`.
 
-  [realise]: #gloss-realise
+    From   the  perspective   of   the  location   where  Nix   is
+    invoked, the  Nix store can be  referred to
+    as a "_local_" or a "_remote_" one:
 
-- [content-addressed derivation]{#gloss-content-addressed-derivation}
+    + A [local store]{#gloss-local-store} exists on the filesystem of
+      the machine where Nix is  invoked. You can use other
+      local stores  by passing  the `--store` flag  to the
+      `nix` command.  Local stores can be used for building derivations.
 
-  A derivation which has the
-  [`__contentAddressed`](./language/advanced-attributes.md#adv-attr-__contentAddressed)
-  attribute set to `true`.
+    + A  *remote store*  exists  anywhere  other than  the
+      local  filesystem. One  example is  the `/nix/store`
+      directory on another machine,  accessed via `ssh` or
+      served by the `nix-serve` Perl script.
 
-- [fixed-output derivation]{#gloss-fixed-output-derivation}
+    [store]: #gloss-store
+    [local store]: #gloss-local-store
 
-  A derivation which includes the
-  [`outputHash`](./language/advanced-attributes.md#adv-attr-outputHash) attribute.
+  - [chroot store]{#gloss-chroot-store}\
+    A [local store] whose canonical path is anything other than `/nix/store`.
 
-- [store]{#gloss-store}
+  - [binary cache]{#gloss-binary-cache}\
+    A *binary cache* is a Nix store which uses a different format: its
+    metadata and signatures are kept in `.narinfo` files rather than in a
+    [Nix database]. This different format simplifies serving store objects
+    over the network, but cannot host builds. Examples of binary caches
+    include S3 buckets and the [NixOS binary cache](https://cache.nixos.org).
 
-  The location in the file system where store objects live. Typically
-  `/nix/store`.
+  - [store path]{#gloss-store-path}\
+    The location of a [store object] in the file system, i.e., an
+    immediate child of the Nix store directory.
 
-  From   the  perspective   of   the  location   where  Nix   is
-  invoked, the  Nix store can be  referred to
-  as a "_local_" or a "_remote_" one:
+    Example: `/nix/store/a040m110amc4h71lds2jmr8qrkj2jhxd-git-2.38.1`
 
-  + A [local store]{#gloss-local-store} exists on the filesystem of
-    the machine where Nix is  invoked. You can use other
-    local stores  by passing  the `--store` flag  to the
-    `nix` command.  Local stores can be used for building derivations.
+    [store path]: #gloss-store-path
 
-  + A  *remote store*  exists  anywhere  other than  the
-    local  filesystem. One  example is  the `/nix/store`
-    directory on another machine,  accessed via `ssh` or
-    served by the `nix-serve` Perl script.
+  - [store object]{#gloss-store-object}\
+    A file that is an immediate child of the Nix store directory. These
+    can be regular files, but also entire directory trees. Store objects
+    can be sources (objects copied from outside of the store),
+    derivation outputs (objects produced by running a build task), or
+    derivations (files describing a build task).
 
-  [store]: #gloss-store
-  [local store]: #gloss-local-store
+    [store object]: #gloss-store-object
 
-- [chroot store]{#gloss-chroot-store}
+  - [input-addressed store object]{#gloss-input-addressed-store-object}\
+    A store object produced by building a
+    non-[content-addressed](#gloss-content-addressed-derivation),
+    non-[fixed-output](#gloss-fixed-output-derivation)
+    derivation.
 
-  A [local store] whose canonical path is anything other than `/nix/store`.
+  - [output-addressed store object]{#gloss-output-addressed-store-object}\
+    A store object whose store path hashes its content.  This
+    includes derivations, the outputs of
+    [content-addressed derivations](#gloss-content-addressed-derivation),
+    and the outputs of
+    [fixed-output derivations](#gloss-fixed-output-derivation).
 
-- [binary cache]{#gloss-binary-cache}
+  - [substitute]{#gloss-substitute}\
+    A substitute is a command invocation stored in the [Nix database] that
+    describes how to build a store object, bypassing the normal build
+    mechanism (i.e., derivations). Typically, the substitute builds the
+    store object by downloading a pre-built version of the store object
+    from some server.
 
-  A *binary cache* is a Nix store which uses a different format: its
-  metadata and signatures are kept in `.narinfo` files rather than in a
-  [Nix database]. This different format simplifies serving store objects
-  over the network, but cannot host builds. Examples of binary caches
-  include S3 buckets and the [NixOS binary cache](https://cache.nixos.org).
+  - [substituter]{#gloss-substituter}\
+    A *substituter* is an additional store from which Nix will
+    copy store objects it doesn't have.  For details, see the
+    [`substituters` option](./command-ref/conf-file.md#conf-substituters).
 
-- [store path]{#gloss-store-path}
+    [substituter]: #gloss-substituter
 
-  The location of a [store object] in the file system, i.e., an
-  immediate child of the Nix store directory.
+  - [purity]{#gloss-purity}\
+    The assumption that equal Nix derivations when run always produce
+    the same output. This cannot be guaranteed in general (e.g., a
+    builder can rely on external inputs such as the network or the
+    system time) but the Nix model assumes it.
 
-  Example: `/nix/store/a040m110amc4h71lds2jmr8qrkj2jhxd-git-2.38.1`
+  - Nix database{#gloss-nix-database}\
+    An SQlite database to track [reference]s between [store object]s.
+    This is an implementation detail of the [local store].
 
-  [store path]: #gloss-store-path
+    Default location: `/nix/var/nix/db`.
 
-- [file system object]{#gloss-store-object}
+    [Nix database]: #gloss-nix-database
 
-  The Nix data model for representing simplified file system data.
+  - [Nix expression]{#gloss-nix-expression}\
+    A high-level description of software packages and compositions
+    thereof. Deploying software using Nix entails writing Nix
+    expressions for your packages. Nix expressions are translated to
+    derivations that are stored in the Nix store. These derivations can
+    then be built.
 
-  See [File System Object](@docroot@/architecture/file-system-object.md) for details.
+  - [reference]{#gloss-reference}\
+    A [store object] `O` is said to have a *reference* to a store object `P` if a [store path] to `P` appears in the contents of `O`.
 
-  [file system object]: #gloss-file-system-object
+    Store objects can refer to both other store objects and themselves.
+    References from a store object to itself are called *self-references*.
+    References other than a self-reference must not form a cycle.
 
-- [store object]{#gloss-store-object}
+    [reference]: #gloss-reference
 
+  - [reachable]{#gloss-reachable}\
+    A store path `Q` is reachable from another store path `P` if `Q`
+    is in the *closure* of the *references* relation.
 
-  A store object consists of a [file system object], [reference]s to other store objects, and other metadata.
-  It can be referred to by a [store path].
+  - [closure]{#gloss-closure}\
+    The closure of a store path is the set of store paths that are
+    directly or indirectly “reachable” from that store path; that is,
+    it’s the closure of the path under the *references* relation. For
+    a package, the closure of its derivation is equivalent to the
+    build-time dependencies, while the closure of its output path is
+    equivalent to its runtime dependencies. For correct deployment it
+    is necessary to deploy whole closures, since otherwise at runtime
+    files could be missing. The command `nix-store -qR` prints out
+    closures of store paths.
 
-  [store object]: #gloss-store-object
+    As an example, if the [store object] at path `P` contains a [reference]
+    to a store object at path `Q`, then `Q` is in the closure of `P`. Further, if `Q`
+    references `R` then `R` is also in the closure of `P`.
 
-- [input-addressed store object]{#gloss-input-addressed-store-object}
+    [closure]: #gloss-closure
 
-  A store object produced by building a
-  non-[content-addressed](#gloss-content-addressed-derivation),
-  non-[fixed-output](#gloss-fixed-output-derivation)
-  derivation.
+  - [output path]{#gloss-output-path}\
+    A [store path] produced by a [derivation].
 
-- [output-addressed store object]{#gloss-output-addressed-store-object}
+    [output path]: #gloss-output-path
 
-  A [store object] whose [store path] is determined by its contents.
-  This includes derivations, the outputs of [content-addressed derivations](#gloss-content-addressed-derivation), and the outputs of [fixed-output derivations](#gloss-fixed-output-derivation).
+  - [deriver]{#gloss-deriver}\
+    The [store derivation] that produced an [output path].
 
-- [substitute]{#gloss-substitute}
+  - [validity]{#gloss-validity}\
+    A store path is valid if all [store object]s in its [closure] can be read from the [store].
 
-  A substitute is a command invocation stored in the [Nix database] that
-  describes how to build a store object, bypassing the normal build
-  mechanism (i.e., derivations). Typically, the substitute builds the
-  store object by downloading a pre-built version of the store object
-  from some server.
+    For a [local store], this means:
+    - The store path leads to an existing [store object] in that [store].
+    - The store path is listed in the [Nix database] as being valid.
+    - All paths in the store path's [closure] are valid.
 
-- [substituter]{#gloss-substituter}
+    [validity]: #gloss-validity
 
-  An additional [store]{#gloss-store} from which Nix can obtain store objects instead of building them.
-  Often the substituter is a [binary cache](#gloss-binary-cache), but any store can serve as substituter.
+  - [user environment]{#gloss-user-env}\
+    An automatically generated store object that consists of a set of
+    symlinks to “active” applications, i.e., other store paths. These
+    are generated automatically by
+    [`nix-env`](./command-ref/nix-env.md). See *profiles*.
 
-  See the [`substituters` configuration option](./command-ref/conf-file.md#conf-substituters) for details.
+  - [profile]{#gloss-profile}\
+    A symlink to the current *user environment* of a user, e.g.,
+    `/nix/var/nix/profiles/default`.
 
-  [substituter]: #gloss-substituter
+  - [installable]{#gloss-installable}\
+    Something that can be realised in the Nix store.
 
-- [purity]{#gloss-purity}
+    See [installables](./command-ref/new-cli/nix.md#installables) for [`nix` commands](./command-ref/new-cli/nix.md) (experimental) for details.
 
-  The assumption that equal Nix derivations when run always produce
-  the same output. This cannot be guaranteed in general (e.g., a
-  builder can rely on external inputs such as the network or the
-  system time) but the Nix model assumes it.
+  - [NAR]{#gloss-nar}\
+    A *N*ix *AR*chive. This is a serialisation of a path in the Nix
+    store. It can contain regular files, directories and symbolic
+    links.  NARs are generated and unpacked using `nix-store --dump`
+    and `nix-store --restore`.
 
-- [Nix database]{#gloss-nix-database}
+  - [`∅`]{#gloss-emtpy-set}\
+    The empty set symbol. In the context of profile history, this denotes a package is not present in a particular version of the profile.
 
-  An SQlite database to track [reference]s between [store object]s.
-  This is an implementation detail of the [local store].
+  - [`ε`]{#gloss-epsilon}\
+    The epsilon symbol. In the context of a package, this means the version is empty. More precisely, the derivation does not have a version attribute.
 
-  Default location: `/nix/var/nix/db`.
+  - [string interpolation]{#gloss-string-interpolation}\
+    Expanding expressions enclosed in `${ }` within a [string], [path], or [attribute name].
 
-  [Nix database]: #gloss-nix-database
+    See [String interpolation](./language/string-interpolation.md) for details.
 
-- [Nix expression]{#gloss-nix-expression}
-
-  A high-level description of software packages and compositions
-  thereof. Deploying software using Nix entails writing Nix
-  expressions for your packages. Nix expressions are translated to
-  derivations that are stored in the Nix store. These derivations can
-  then be built.
-
-- [reference]{#gloss-reference}
-
-  A [store object] `O` is said to have a *reference* to a store object `P` if a [store path] to `P` appears in the contents of `O`.
-
-  Store objects can refer to both other store objects and themselves.
-  References from a store object to itself are called *self-references*.
-  References other than a self-reference must not form a cycle.
-
-  [reference]: #gloss-reference
-
-- [reachable]{#gloss-reachable}
-
-  A store path `Q` is reachable from another store path `P` if `Q`
-  is in the *closure* of the *references* relation.
-
-- [closure]{#gloss-closure}
-
-  The closure of a store path is the set of store paths that are
-  directly or indirectly “reachable” from that store path; that is,
-  it’s the closure of the path under the *references* relation. For
-  a package, the closure of its derivation is equivalent to the
-  build-time dependencies, while the closure of its output path is
-  equivalent to its runtime dependencies. For correct deployment it
-  is necessary to deploy whole closures, since otherwise at runtime
-  files could be missing. The command `nix-store --query --requisites ` prints out
-  closures of store paths.
-
-  As an example, if the [store object] at path `P` contains a [reference]
-  to a store object at path `Q`, then `Q` is in the closure of `P`. Further, if `Q`
-  references `R` then `R` is also in the closure of `P`.
-
-  [closure]: #gloss-closure
-
-- [output]{#gloss-output}
-
-  A [store object] produced by a [derivation].
-
-  [output]: #gloss-output
-
-- [output path]{#gloss-output-path}
-
-  The [store path] to the [output] of a [derivation].
-
-  [output path]: #gloss-output-path
-
-- [deriver]{#gloss-deriver}
-
-  The [store derivation] that produced an [output path].
-
-- [validity]{#gloss-validity}
-
-  A store path is valid if all [store object]s in its [closure] can be read from the [store].
-
-  For a [local store], this means:
-  - The store path leads to an existing [store object] in that [store].
-  - The store path is listed in the [Nix database] as being valid.
-  - All paths in the store path's [closure] are valid.
-
-  [validity]: #gloss-validity
-
-- [user environment]{#gloss-user-env}
-
-  An automatically generated store object that consists of a set of
-  symlinks to “active” applications, i.e., other store paths. These
-  are generated automatically by
-  [`nix-env`](./command-ref/nix-env.md). See *profiles*.
-
-- [profile]{#gloss-profile}
-
-  A symlink to the current *user environment* of a user, e.g.,
-  `/nix/var/nix/profiles/default`.
-
-- [installable]{#gloss-installable}
-
-  Something that can be realised in the Nix store.
-
-  See [installables](./command-ref/new-cli/nix.md#installables) for [`nix` commands](./command-ref/new-cli/nix.md) (experimental) for details.
-
-- [NAR]{#gloss-nar}
-
-  A *N*ix *AR*chive. This is a serialisation of a path in the Nix
-  store. It can contain regular files, directories and symbolic
-  links.  NARs are generated and unpacked using `nix-store --dump`
-  and `nix-store --restore`.
-
-- [`∅`]{#gloss-emtpy-set}
-
-  The empty set symbol. In the context of profile history, this denotes a package is not present in a particular version of the profile.
-
-- [`ε`]{#gloss-epsilon}
-
-  The epsilon symbol. In the context of a package, this means the version is empty. More precisely, the derivation does not have a version attribute.
-
-- [string interpolation]{#gloss-string-interpolation}
-
-  Expanding expressions enclosed in `${ }` within a [string], [path], or [attribute name].
-
-  See [String interpolation](./language/string-interpolation.md) for details.
-
-  [string]: ./language/values.md#type-string
-  [path]: ./language/values.md#type-path
-  [attribute name]: ./language/values.md#attribute-set
-
-- [experimental feature]{#gloss-experimental-feature}
-
-  Not yet stabilized functionality guarded by named experimental feature flags.
-  These flags are enabled or disabled with the [`experimental-features`](./command-ref/conf-file.html#conf-experimental-features) setting.
-
-  See the contribution guide on the [purpose and lifecycle of experimental feaures](@docroot@/contributing/experimental-features.md).
+    [string]: ./language/values.md#type-string
+    [path]: ./language/values.md#type-path
+    [attribute name]: ./language/values.md#attribute-set

doc/manual/src/installation/installing-binary.md

@@ -47,6 +47,12 @@ The install script will modify the first writable file from amongst
 `NIX_INSTALLER_NO_MODIFY_PROFILE` environment variable before executing
 the install script to disable this behaviour.
 
+You can uninstall Nix simply by running:
+
+```console
+$ rm -rf /nix
+```
+
 # Multi User Installation
 
 The multi-user Nix installation creates system users, and a system
@@ -78,8 +84,154 @@ The installer will modify `/etc/bashrc`, and `/etc/zshrc` if they exist.
 The installer will first back up these files with a `.backup-before-nix`
 extension. The installer will also create `/etc/profile.d/nix.sh`.
 
-# macOS Installation
+## Uninstalling
 
+### Linux
+
+If you are on Linux with systemd:
+
+1. Remove the Nix daemon service:
+
+   ```console
+   sudo systemctl stop nix-daemon.service
+   sudo systemctl disable nix-daemon.socket nix-daemon.service
+   sudo systemctl daemon-reload
+   ```
+
+1. Remove systemd service files:
+
+   ```console
+   sudo rm /etc/systemd/system/nix-daemon.service /etc/systemd/system/nix-daemon.socket
+   ```
+
+1. The installer script uses systemd-tmpfiles to create the socket directory.
+    You may also want to remove the configuration for that:
+
+   ```console
+   sudo rm /etc/tmpfiles.d/nix-daemon.conf
+   ```
+
+Remove files created by Nix:
+
+```console
+sudo rm -rf /nix /etc/nix /etc/profile/nix.sh ~root/.nix-profile ~root/.nix-defexpr ~root/.nix-channels ~/.nix-profile ~/.nix-defexpr ~/.nix-channels
+```
+
+Remove build users and their group:
+
+```console
+for i in $(seq 1 32); do
+  sudo userdel nixbld$i
+done
+sudo groupdel nixbld
+```
+
+There may also be references to Nix in
+
+- `/etc/profile`
+- `/etc/bashrc`
+- `/etc/zshrc`
+
+which you may remove.
+
+### macOS
+
+1. Edit `/etc/zshrc` and `/etc/bashrc` to remove the lines sourcing
+   `nix-daemon.sh`, which should look like this:
+
+   ```bash
+   # Nix
+   if [ -e '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh' ]; then
+     . '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh'
+   fi
+   # End Nix
+   ```
+
+   If these files haven't been altered since installing Nix you can simply put
+   the backups back in place:
+
+   ```console
+   sudo mv /etc/zshrc.backup-before-nix /etc/zshrc
+   sudo mv /etc/bashrc.backup-before-nix /etc/bashrc
+   ```
+
+   This will stop shells from sourcing the file and bringing everything you
+   installed using Nix in scope.
+
+2. Stop and remove the Nix daemon services:
+
+   ```console
+   sudo launchctl unload /Library/LaunchDaemons/org.nixos.nix-daemon.plist
+   sudo rm /Library/LaunchDaemons/org.nixos.nix-daemon.plist
+   sudo launchctl unload /Library/LaunchDaemons/org.nixos.darwin-store.plist
+   sudo rm /Library/LaunchDaemons/org.nixos.darwin-store.plist
+   ```
+
+   This stops the Nix daemon and prevents it from being started next time you
+   boot the system.
+
+3. Remove the `nixbld` group and the `_nixbuildN` users:
+
+   ```console
+   sudo dscl . -delete /Groups/nixbld
+   for u in $(sudo dscl . -list /Users | grep _nixbld); do sudo dscl . -delete /Users/$u; done
+   ```
+
+   This will remove all the build users that no longer serve a purpose.
+
+4. Edit fstab using `sudo vifs` to remove the line mounting the Nix Store
+   volume on `/nix`, which looks like
+   `UUID=<uuid> /nix apfs rw,noauto,nobrowse,suid,owners` or
+   `LABEL=Nix\040Store /nix apfs rw,nobrowse`. This will prevent automatic
+   mounting of the Nix Store volume.
+
+5. Edit `/etc/synthetic.conf` to remove the `nix` line. If this is the only
+   line in the file you can remove it entirely, `sudo rm /etc/synthetic.conf`.
+   This will prevent the creation of the empty `/nix` directory to provide a
+   mountpoint for the Nix Store volume.
+
+6. Remove the files Nix added to your system:
+
+   ```console
+   sudo rm -rf /etc/nix /var/root/.nix-profile /var/root/.nix-defexpr /var/root/.nix-channels ~/.nix-profile ~/.nix-defexpr ~/.nix-channels
+   ```
+
+   This gets rid of any data Nix may have created except for the store which is
+   removed next.
+
+7. Remove the Nix Store volume:
+
+   ```console
+   sudo diskutil apfs deleteVolume /nix
+   ```
+
+   This will remove the Nix Store volume and everything that was added to the
+   store.
+
+   If the output indicates that the command couldn't remove the volume, you should
+   make sure you don't have an _unmounted_ Nix Store volume. Look for a
+   "Nix Store" volume in the output of the following command:
+
+   ```console
+   diskutil list
+   ```
+
+   If you _do_ see a "Nix Store" volume, delete it by re-running the diskutil
+   deleteVolume command, but replace `/nix` with the store volume's `diskXsY`
+   identifier.
+
+> **Note**
+>
+> After you complete the steps here, you will still have an empty `/nix`
+> directory. This is an expected sign of a successful uninstall. The empty
+> `/nix` directory will disappear the next time you reboot.
+>
+> You do not have to reboot to finish uninstalling Nix. The uninstall is
+> complete. macOS (Catalina+) directly controls root directories and its
+> read-only root will prevent you from manually deleting the empty `/nix`
+> mountpoint.
+
+# macOS Installation
 []{#sect-macos-installation-change-store-prefix}[]{#sect-macos-installation-encrypted-volume}[]{#sect-macos-installation-symlink}[]{#sect-macos-installation-recommended-notes}
 <!-- Note: anchors above to catch permalinks to old explanations -->
 
@@ -128,16 +280,19 @@ this to run the installer, but it may help if you run into trouble:
 
 # Installing a pinned Nix version from a URL
 
-Version-specific installation URLs for all Nix versions
-since 1.11.16 can be found at [releases.nixos.org](https://releases.nixos.org/?prefix=nix/).
-The corresponding SHA-256 hash can be found in the directory for the given version.
+NixOS.org hosts version-specific installation URLs for all Nix versions
+since 1.11.16, at `https://releases.nixos.org/nix/nix-version/install`.
 
-These install scripts can be used the same as usual:
+These install scripts can be used the same as the main NixOS.org
+installation script:
 
 ```console
-$ curl -L https://releases.nixos.org/nix/nix-<version>/install | sh
+$ curl -L https://nixos.org/nix/install | sh
 ```
 
+In the same directory of the install script are sha256 sums, and gpg
+signature files.
+
 # Installing from a binary tarball
 
 You can also download a binary tarball that contains Nix and all its

doc/manual/src/installation/prerequisites-source.md

@@ -10,7 +10,7 @@
   - Bash Shell. The `./configure` script relies on bashisms, so Bash is
     required.
 
-  - A version of GCC or Clang that supports C++20.
+  - A version of GCC or Clang that supports C++17.
 
   - `pkg-config` to locate dependencies. If your distribution does not
     provide it, you can get it from

doc/manual/src/installation/uninstall.md

@@ -1,148 +0,0 @@
-# Uninstalling Nix
-
-## Single User
-
-If you have a [single-user installation](./installing-binary.md#single-user-installation) of Nix, uninstall it by running:
-
-```console
-$ rm -rf /nix
-```
-
-## Multi User
-
-Removing a [multi-user installation](./installing-binary.md#multi-user-installation) of Nix is more involved, and depends on the operating system.
-
-### Linux
-
-If you are on Linux with systemd:
-
-1. Remove the Nix daemon service:
-
-   ```console
-   sudo systemctl stop nix-daemon.service
-   sudo systemctl disable nix-daemon.socket nix-daemon.service
-   sudo systemctl daemon-reload
-   ```
-
-Remove files created by Nix:
-
-```console
-sudo rm -rf /etc/nix /etc/profile.d/nix.sh /etc/tmpfiles.d/nix-daemon.conf /nix ~root/.nix-channels ~root/.nix-defexpr ~root/.nix-profile
-```
-
-Remove build users and their group:
-
-```console
-for i in $(seq 1 32); do
-  sudo userdel nixbld$i
-done
-sudo groupdel nixbld
-```
-
-There may also be references to Nix in
-
-- `/etc/bash.bashrc`
-- `/etc/bashrc`
-- `/etc/profile`
-- `/etc/zsh/zshrc`
-- `/etc/zshrc`
-
-which you may remove.
-
-### macOS
-
-1. Edit `/etc/zshrc`, `/etc/bashrc`, and `/etc/bash.bashrc` to remove the lines sourcing `nix-daemon.sh`, which should look like this:
-
-   ```bash
-   # Nix
-   if [ -e '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh' ]; then
-     . '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh'
-   fi
-   # End Nix
-   ```
-
-   If these files haven't been altered since installing Nix you can simply put
-   the backups back in place:
-
-   ```console
-   sudo mv /etc/zshrc.backup-before-nix /etc/zshrc
-   sudo mv /etc/bashrc.backup-before-nix /etc/bashrc
-   sudo mv /etc/bash.bashrc.backup-before-nix /etc/bash.bashrc
-   ```
-
-   This will stop shells from sourcing the file and bringing everything you
-   installed using Nix in scope.
-
-2. Stop and remove the Nix daemon services:
-
-   ```console
-   sudo launchctl unload /Library/LaunchDaemons/org.nixos.nix-daemon.plist
-   sudo rm /Library/LaunchDaemons/org.nixos.nix-daemon.plist
-   sudo launchctl unload /Library/LaunchDaemons/org.nixos.darwin-store.plist
-   sudo rm /Library/LaunchDaemons/org.nixos.darwin-store.plist
-   ```
-
-   This stops the Nix daemon and prevents it from being started next time you
-   boot the system.
-
-3. Remove the `nixbld` group and the `_nixbuildN` users:
-
-   ```console
-   sudo dscl . -delete /Groups/nixbld
-   for u in $(sudo dscl . -list /Users | grep _nixbld); do sudo dscl . -delete /Users/$u; done
-   ```
-
-   This will remove all the build users that no longer serve a purpose.
-
-4. Edit fstab using `sudo vifs` to remove the line mounting the Nix Store
-   volume on `/nix`, which looks like
-   `UUID=<uuid> /nix apfs rw,noauto,nobrowse,suid,owners` or
-   `LABEL=Nix\040Store /nix apfs rw,nobrowse`. This will prevent automatic
-   mounting of the Nix Store volume.
-
-5. Edit `/etc/synthetic.conf` to remove the `nix` line. If this is the only
-   line in the file you can remove it entirely, `sudo rm /etc/synthetic.conf`.
-   This will prevent the creation of the empty `/nix` directory to provide a
-   mountpoint for the Nix Store volume.
-
-6. Remove the files Nix added to your system:
-
-   ```console
-   sudo rm -rf /etc/nix /var/root/.nix-profile /var/root/.nix-defexpr /var/root/.nix-channels ~/.nix-profile ~/.nix-defexpr ~/.nix-channels
-   ```
-
-   This gets rid of any data Nix may have created except for the store which is
-   removed next.
-
-7. Remove the Nix Store volume:
-
-   ```console
-   sudo diskutil apfs deleteVolume /nix
-   ```
-
-   This will remove the Nix Store volume and everything that was added to the
-   store.
-
-   If the output indicates that the command couldn't remove the volume, you should
-   make sure you don't have an _unmounted_ Nix Store volume. Look for a
-   "Nix Store" volume in the output of the following command:
-
-   ```console
-   diskutil list
-   ```
-
-   If you _do_ see a "Nix Store" volume, delete it by re-running the diskutil
-   deleteVolume command, but replace `/nix` with the store volume's `diskXsY`
-   identifier.
-
-> **Note**
->
-> After you complete the steps here, you will still have an empty `/nix`
-> directory. This is an expected sign of a successful uninstall. The empty
-> `/nix` directory will disappear the next time you reboot.
->
-> You do not have to reboot to finish uninstalling Nix. The uninstall is
-> complete. macOS (Catalina+) directly controls root directories and its
-> read-only root will prevent you from manually deleting the empty `/nix`
-> mountpoint.
-

doc/manual/src/installation/upgrading.md

@@ -2,13 +2,13 @@
 
 Multi-user Nix users on macOS can upgrade Nix by running: `sudo -i sh -c
 'nix-channel --update &&
-nix-env --install --attr nixpkgs.nix &&
+nix-env -iA nixpkgs.nix &&
 launchctl remove org.nixos.nix-daemon &&
 launchctl load /Library/LaunchDaemons/org.nixos.nix-daemon.plist'`
 
 Single-user installations of Nix should run this: `nix-channel --update;
-nix-env --install --attr nixpkgs.nix nixpkgs.cacert`
+nix-env -iA nixpkgs.nix nixpkgs.cacert`
 
 Multi-user Nix users on Linux should run this with sudo: `nix-channel
---update; nix-env --install --attr nixpkgs.nix nixpkgs.cacert; systemctl
+--update; nix-env -iA nixpkgs.nix nixpkgs.cacert; systemctl
 daemon-reload; systemctl restart nix-daemon`

doc/manual/src/introduction.md

@@ -76,7 +76,7 @@ there after an upgrade.  This means that you can _roll back_ to the
 old version:
 
 ```console
-$ nix-env --upgrade --attr nixpkgs.some-package
+$ nix-env --upgrade -A nixpkgs.some-package
 $ nix-env --rollback
 ```
 
@@ -122,7 +122,7 @@ Nix expressions generally describe how to build a package from
 source, so an installation action like
 
 ```console
-$ nix-env --install --attr nixpkgs.firefox
+$ nix-env --install -A nixpkgs.firefox
 ```
 
 _could_ cause quite a bit of build activity, as not only Firefox but
@@ -158,7 +158,7 @@ Pan newsreader, as described by [its
 Nix expression](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/networking/newsreaders/pan/default.nix):
 
 ```console
-$ nix-shell '<nixpkgs>' --attr pan
+$ nix-shell '<nixpkgs>' -A pan
 ```
 
 You’re then dropped into a shell where you can edit, build and test

doc/manual/src/language/advanced-attributes.md

@@ -208,26 +208,12 @@ Derivations can declare some infrequently used optional attributes.
     about converting to and from base-32 notation.)
 
   - [`__contentAddressed`]{#adv-attr-__contentAddressed}
-    > **Warning**
-    > This attribute is part of an [experimental feature](@docroot@/contributing/experimental-features.md).
-    >
-    > To use this attribute, you must enable the
-    > [`ca-derivations`](@docroot@/contributing/experimental-features.md#xp-feature-ca-derivations) experimental feature.
-    > For example, in [nix.conf](../command-ref/conf-file.md) you could add:
-    >
-    > ```
-    > extra-experimental-features = ca-derivations
-    > ```
-
-    If this attribute is set to `true`, then the derivation
+    If this **experimental** attribute is set to true, then the derivation
     outputs will be stored in a content-addressed location rather than the
     traditional input-addressed one.
+    This only has an effect if the `ca-derivations` experimental feature is enabled.
 
-    Setting this attribute also requires setting
-    [`outputHashMode`](#adv-attr-outputHashMode)
-    and
-    [`outputHashAlgo`](#adv-attr-outputHashAlgo)
-    like for *fixed-output derivations* (see above).
+    Setting this attribute also requires setting `outputHashMode` and `outputHashAlgo` like for *fixed-output derivations* (see above).
 
   - [`passAsFile`]{#adv-attr-passAsFile}\
     A list of names of attributes that should be passed via files rather
@@ -320,6 +306,14 @@ Derivations can declare some infrequently used optional attributes.
     ```
 
   - [`unsafeDiscardReferences`]{#adv-attr-unsafeDiscardReferences}\
+    > **Warning**
+    > This is an experimental feature.
+    >
+    > To enable it, add the following to [nix.conf](../command-ref/conf-file.md):
+    >
+    > ```
+    > extra-experimental-features = discard-references
+    > ```
 
     When using [structured attributes](#adv-attr-structuredAttrs), the
     attribute `unsafeDiscardReferences` is an attribute set with a boolean value for each output name.

doc/manual/src/language/builtin-constants-prefix.md

@@ -1,5 +0,0 @@
-# Built-in Constants
-
-These constants are built into the Nix language evaluator:
-
-<dl>

doc/manual/src/language/builtin-constants-suffix.md

@@ -1 +0,0 @@
-</dl>

doc/manual/src/language/builtin-constants.md

@@ -0,0 +1,20 @@
+# Built-in Constants
+
+Here are the constants built into the Nix expression evaluator:
+
+  - `builtins`\
+    The set `builtins` contains all the built-in functions and values.
+    You can use `builtins` to test for the availability of features in
+    the Nix installation, e.g.,
+    
+    ```nix
+    if builtins ? getEnv then builtins.getEnv "PATH" else ""
+    ```
+    
+    This allows a Nix expression to fall back gracefully on older Nix
+    installations that don’t have the desired built-in function.
+
+  - [`builtins.currentSystem`]{#builtins-currentSystem}\
+    The built-in value `currentSystem` evaluates to the Nix platform
+    identifier for the Nix installation on which the expression is being
+    evaluated, such as `"i686-linux"` or `"x86_64-darwin"`.

doc/manual/src/language/builtins-prefix.md

@@ -1,16 +1,16 @@
 # Built-in Functions
 
-This section lists the functions built into the Nix language evaluator.
-All built-in functions are available through the global [`builtins`](./builtin-constants.md#builtins-builtins) constant.
-
-For convenience, some built-ins can be accessed directly:
-
-- [`derivation`](#builtins-derivation)
-- [`import`](#builtins-import)
-- [`abort`](#builtins-abort)
-- [`throw`](#builtins-throw)
+This section lists the functions built into the Nix expression
+evaluator. (The built-in function `derivation` is discussed above.)
+Some built-ins, such as `derivation`, are always in scope of every Nix
+expression; you can just access them right away. But to prevent
+polluting the namespace too much, most built-ins are not in
+scope. Instead, you can access them through the `builtins` built-in
+value, which is a set that contains all built-in functions and values.
+For instance, `derivation` is also available as `builtins.derivation`.
 
 <dl>
-  <dt id="builtins-derivation"><a href="#builtins-derivation"><code>derivation <var>attrs</var></code></a></dt>
+  <dt><code>derivation <var>attrs</var></code>;
+      <code>builtins.derivation <var>attrs</var></code></dt>
   <dd><p><var>derivation</var> is described in
          <a href="derivations.md">its own section</a>.</p></dd>

doc/manual/src/language/constructs.md

@@ -2,11 +2,8 @@
 
 ## Recursive sets
 
-Recursive sets are like normal [attribute sets](./values.md#attribute-set), but the attributes can refer to each other.
-
-> *rec-attrset* = `rec {` [ *name* `=` *expr* `;` `]`... `}`
-
-Example:
+Recursive sets are just normal sets, but the attributes can refer to
+each other. For example,
 
 ```nix
 rec {
@@ -15,9 +12,7 @@ rec {
 }.x
 ```
 
-This evaluates to `123`.
-
-Note that without `rec` the binding `x = y;` would
+evaluates to `123`. Note that without `rec` the binding `x = y;` would
 refer to the variable `y` in the surrounding scope, if one exists, and
 would be invalid if no such variable exists. That is, in a normal
 (non-recursive) set, attributes are not added to the lexical scope; in a
@@ -38,10 +33,7 @@ will crash with an `infinite recursion encountered` error message.
 ## Let-expressions
 
 A let-expression allows you to define local variables for an expression.
-
-> *let-in* = `let` [ *identifier* = *expr* ]... `in` *expr*
-
-Example:
+For instance,
 
 ```nix
 let
@@ -50,19 +42,18 @@ let
 in x + y
 ```
 
-This evaluates to `"foobar"`.
+evaluates to `"foobar"`.
 
 ## Inheriting attributes
 
-When defining an [attribute set](./values.md#attribute-set) or in a [let-expression](#let-expressions) it is often convenient to copy variables from the surrounding lexical scope (e.g., when you want to propagate attributes).
-This can be shortened using the `inherit` keyword.
-
-Example:
+When defining a set or in a let-expression it is often convenient to
+copy variables from the surrounding lexical scope (e.g., when you want
+to propagate attributes). This can be shortened using the `inherit`
+keyword. For instance,
 
 ```nix
 let x = 123; in
-{
-  inherit x;
+{ inherit x;
   y = 456;
 }
 ```
@@ -71,31 +62,23 @@ is equivalent to
 
 ```nix
 let x = 123; in
-{
-  x = x;
+{ x = x;
   y = 456;
 }
 ```
 
-and both evaluate to `{ x = 123; y = 456; }`.
-
-> **Note**
->
-> This works because `x` is added to the lexical scope by the `let` construct.
-
-It is also possible to inherit attributes from another attribute set.
-
-Example:
-
-In this fragment from `all-packages.nix`,
+and both evaluate to `{ x = 123; y = 456; }`. (Note that this works
+because `x` is added to the lexical scope by the `let` construct.) It is
+also possible to inherit attributes from another set. For instance, in
+this fragment from `all-packages.nix`,
 
 ```nix
 graphviz = (import ../tools/graphics/graphviz) {
   inherit fetchurl stdenv libpng libjpeg expat x11 yacc;
-  inherit (xorg) libXaw;
+  inherit (xlibs) libXaw;
 };
 
-xorg = {
+xlibs = {
   libX11 = ...;
   libXaw = ...;
   ...
@@ -109,7 +92,7 @@ libjpg = ...;
 the set used in the function call to the function defined in
 `../tools/graphics/graphviz` inherits a number of variables from the
 surrounding scope (`fetchurl` ... `yacc`), but also inherits `libXaw`
-(the X Athena Widgets) from the `xorg` set.
+(the X Athena Widgets) from the `xlibs` (X11 client-side libraries) set.
 
 Summarizing the fragment
 
@@ -208,41 +191,30 @@ three kinds of patterns:
     ```nix
     { x, y, z, ... } @ args: z + y + x + args.a
     ```
-
-    Here `args` is bound to the argument *as passed*, which is further
-    matched against the pattern `{ x, y, z, ... }`.
-    The `@`-pattern makes mainly sense with an ellipsis(`...`) as
+    
+    Here `args` is bound to the entire argument, which is further
+    matched against the pattern `{ x, y, z,
+            ... }`. `@`-pattern makes mainly sense with an ellipsis(`...`) as
     you can access attribute names as `a`, using `args.a`, which was
     given as an additional attribute to the function.
-
+    
     > **Warning**
-    >
-    > `args@` binds the name `args` to the attribute set that is passed to the function.
-    > In particular, `args` does *not* include any default values specified with `?` in the function's set pattern.
-    >
+    > 
+    > The `args@` expression is bound to the argument passed to the
+    > function which means that attributes with defaults that aren't
+    > explicitly specified in the function call won't cause an
+    > evaluation error, but won't exist in `args`.
+    > 
     > For instance
-    >
+    > 
     > ```nix
     > let
-    >   f = args@{ a ? 23, ... }: [ a args ];
+    >   function = args@{ a ? 23, ... }: args;
     > in
-    >   f {}
-    > ```
-    >
-    > is equivalent to
-    >
-    > ```nix
-    > let
-    >   f = args @ { ... }: [ (args.a or 23) args ];
-    > in
-    >   f {}
-    > ```
-    >
-    > and both expressions will evaluate to:
-    >
-    > ```nix
-    > [ 23 {} ]
-    > ```
+    >   function {}
+    > ````
+    > 
+    > will evaluate to an empty attribute set.
 
 Note that functions do not have names. If you want to give them a name,
 you can bind them to an attribute, e.g.,

doc/manual/src/language/derivations.md

@@ -17,7 +17,7 @@ the attributes of which specify the inputs of the build.
     string. This is used as a symbolic name for the package by
     `nix-env`, and it is appended to the output paths of the derivation.
 
-  - There must be an attribute named [`builder`]{#attr-builder} that identifies the
+  - There must be an attribute named `builder` that identifies the
     program that is executed to perform the build. It can be either a
     derivation or a source (a local file reference, e.g.,
     `./builder.sh`).

doc/manual/src/language/index.md

@@ -1,11 +1,12 @@
 # Nix Language
 
-The Nix language is designed for conveniently creating and composing *derivations* – precise descriptions of how contents of existing files are used to derive new files.
-It is:
+The Nix language is
 
 - *domain-specific*
 
-  It comes with [built-in functions](@docroot@/language/builtins.md) to integrate with the Nix store, which manages files and performs the derivations declared in the Nix language.
+  It only exists for the Nix package manager:
+  to describe packages and configurations as well as their variants and compositions.
+  It is not intended for general purpose use.
 
 - *declarative*
 
@@ -24,7 +25,7 @@ It is:
 
 - *lazy*
 
-  Values are only computed when they are needed.
+  Expressions are only evaluated when their value is needed.
 
 - *dynamically typed*
 

doc/manual/src/language/operators.md

@@ -35,14 +35,17 @@
 
 ## Attribute selection
 
-> *attrset* `.` *attrpath* \[ `or` *expr* \]
-
 Select the attribute denoted by attribute path *attrpath* from [attribute set] *attrset*.
-If the attribute doesn’t exist, return the *expr* after `or` if provided, otherwise abort evaluation.
+If the attribute doesn’t exist, return *value* if provided, otherwise abort evaluation.
 
-An attribute path is a dot-separated list of [attribute names](./values.md#attribute-set).
+<!-- FIXME: the following should to into its own language syntax section, but that needs more work to fit in well -->
 
-> *attrpath* = *name* [ `.` *name* ]...
+An attribute path is a dot-separated list of attribute names.
+An attribute name can be an identifier or a string.
+
+> *attrpath* = *name* [ `.` *name* ]... \
+> *name* = *identifier* | *string* \
+> *identifier* ~ `[a-zA-Z_][a-zA-Z0-9_'-]*`
 
 [Attribute selection]: #attribute-selection
 

doc/manual/src/language/values.md

@@ -164,17 +164,9 @@ Note that lists are only lazy in values, and they are strict in length.
 
 An attribute set is a collection of name-value-pairs (called *attributes*) enclosed in curly brackets (`{ }`).
 
-An attribute name can be an identifier or a [string](#string).
-An identifier must start with a letter (`a-z`, `A-Z`) or underscore (`_`), and can otherwise contain letters (`a-z`, `A-Z`), numbers (`0-9`), underscores (`_`), apostrophes (`'`), or dashes (`-`).
-
-> *name* = *identifier* | *string* \
-> *identifier* ~ `[a-zA-Z_][a-zA-Z0-9_'-]*`
-
 Names and values are separated by an equal sign (`=`).
 Each value is an arbitrary expression terminated by a semicolon (`;`).
 
-> *attrset* = `{` [ *name* `=` *expr* `;` `]`... `}`
-
 Attributes can appear in any order.
 An attribute name may only occur once.
 
@@ -190,29 +182,21 @@ Example:
 
 This defines a set with attributes named `x`, `text`, `y`.
 
-Attributes can be accessed with the [`.` operator](./operators.md#attribute-selection).
-
-Example:
+Attributes can be selected from a set using the `.` operator. For
+instance,
 
 ```nix
 { a = "Foo"; b = "Bar"; }.a
 ```
 
-This evaluates to `"Foo"`.
-
-It is possible to provide a default value in an attribute selection using the `or` keyword.
-
-Example:
+evaluates to `"Foo"`. It is possible to provide a default value in an
+attribute selection using the `or` keyword. For example,
 
 ```nix
 { a = "Foo"; b = "Bar"; }.c or "Xyzzy"
 ```
 
-```nix
-{ a = "Foo"; b = "Bar"; }.c.d.e.f.g or "Xyzzy"
-```
-
-will both evaluate to `"Xyzzy"` because there is no `c` attribute in the set.
+will evaluate to `"Xyzzy"` because there is no `c` attribute in the set.
 
 You can use arbitrary double-quoted strings as attribute names:
 

doc/manual/src/package-management/basic-package-mgmt.md

@@ -25,7 +25,7 @@ or completely new ones.)
 
 You can manually download the latest version of Nixpkgs from
 <https://github.com/NixOS/nixpkgs>. However, it’s much more
-convenient to use the Nixpkgs [*channel*](../command-ref/nix-channel.md), since it makes
+convenient to use the Nixpkgs [*channel*](channels.md), since it makes
 it easy to stay up to date with new versions of Nixpkgs. Nixpkgs is
 automatically added to your list of “subscribed” channels when you
 install Nix. If this is not the case for some reason, you can add it
@@ -47,7 +47,7 @@ $ nix-channel --update
 You can view the set of available packages in Nixpkgs:
 
 ```console
-$ nix-env --query --available --attr-path
+$ nix-env -qaP
 nixpkgs.aterm                       aterm-2.2
 nixpkgs.bash                        bash-3.0
 nixpkgs.binutils                    binutils-2.15
@@ -65,7 +65,7 @@ If you downloaded Nixpkgs yourself, or if you checked it out from GitHub,
 then you need to pass the path to your Nixpkgs tree using the `-f` flag:
 
 ```console
-$ nix-env --query --available --attr-path --file /path/to/nixpkgs
+$ nix-env -qaPf /path/to/nixpkgs
 aterm                               aterm-2.2
 bash                                bash-3.0
 …
@@ -77,7 +77,7 @@ Nixpkgs.
 You can filter the packages by name:
 
 ```console
-$ nix-env --query --available --attr-path firefox
+$ nix-env -qaP firefox
 nixpkgs.firefox-esr                 firefox-91.3.0esr
 nixpkgs.firefox                     firefox-94.0.1
 ```
@@ -85,7 +85,7 @@ nixpkgs.firefox                     firefox-94.0.1
 and using regular expressions:
 
 ```console
-$ nix-env --query --available --attr-path 'firefox.*'
+$ nix-env -qaP 'firefox.*'
 ```
 
 It is also possible to see the *status* of available packages, i.e.,
@@ -93,7 +93,7 @@ whether they are installed into the user environment and/or present in
 the system:
 
 ```console
-$ nix-env --query --available --attr-path --status
+$ nix-env -qaPs
 …
 -PS  nixpkgs.bash                bash-3.0
 --S  nixpkgs.binutils            binutils-2.15
@@ -110,10 +110,10 @@ which is Nix’s mechanism for doing binary deployment. It just means that
 Nix knows that it can fetch a pre-built package from somewhere
 (typically a network server) instead of building it locally.
 
-You can install a package using `nix-env --install --attr `. For instance,
+You can install a package using `nix-env -iA`. For instance,
 
 ```console
-$ nix-env --install --attr nixpkgs.subversion
+$ nix-env -iA nixpkgs.subversion
 ```
 
 will install the package called `subversion` from `nixpkgs` channel (which is, of course, the
@@ -143,14 +143,14 @@ instead of the attribute path, as `nix-env` does not record which attribute
 was used for installing:
 
 ```console
-$ nix-env --uninstall subversion
+$ nix-env -e subversion
 ```
 
 Upgrading to a new version is just as easy. If you have a new release of
 Nix Packages, you can do:
 
 ```console
-$ nix-env --upgrade --attr nixpkgs.subversion
+$ nix-env -uA nixpkgs.subversion
 ```
 
 This will *only* upgrade Subversion if there is a “newer” version in the
@@ -163,15 +163,15 @@ whatever version is in the Nix expressions, use `-i` instead of `-u`;
 You can also upgrade all packages for which there are newer versions:
 
 ```console
-$ nix-env --upgrade
+$ nix-env -u
 ```
 
 Sometimes it’s useful to be able to ask what `nix-env` would do, without
 actually doing it. For instance, to find out what packages would be
-upgraded by `nix-env --upgrade `, you can do
+upgraded by `nix-env -u`, you can do
 
 ```console
-$ nix-env --upgrade --dry-run
+$ nix-env -u --dry-run
 (dry run; not doing anything)
 upgrading `libxslt-1.1.0' to `libxslt-1.1.10'
 upgrading `graphviz-1.10' to `graphviz-1.12'

doc/manual/src/package-management/binary-cache-substituter.md

@@ -9,7 +9,7 @@ The daemon that handles binary cache requests via HTTP, `nix-serve`, is
 not part of the Nix distribution, but you can install it from Nixpkgs:
 
 ```console
-$ nix-env --install --attr nixpkgs.nix-serve
+$ nix-env -iA nixpkgs.nix-serve
 ```
 
 You can then start the server, listening for HTTP connections on
@@ -35,7 +35,7 @@ On the client side, you can tell Nix to use your binary cache using
 `--substituters`, e.g.:
 
 ```console
-$ nix-env --install --attr nixpkgs.firefox --substituters http://avalon:8080/
+$ nix-env -iA nixpkgs.firefox --substituters http://avalon:8080/
 ```
 
 The option `substituters` tells Nix to use this binary cache in

doc/manual/src/package-management/channels.md

@@ -0,0 +1,50 @@
+# Channels
+
+If you want to stay up to date with a set of packages, it’s not very
+convenient to manually download the latest set of Nix expressions for
+those packages and upgrade using `nix-env`. Fortunately, there’s a
+better way: *Nix channels*.
+
+A Nix channel is just a URL that points to a place that contains a set
+of Nix expressions and a manifest. Using the command
+[`nix-channel`](../command-ref/nix-channel.md) you can automatically
+stay up to date with whatever is available at that URL.
+
+To see the list of official NixOS channels, visit
+<https://nixos.org/channels>.
+
+You can “subscribe” to a channel using `nix-channel --add`, e.g.,
+
+```console
+$ nix-channel --add https://nixos.org/channels/nixpkgs-unstable
+```
+
+subscribes you to a channel that always contains that latest version of
+the Nix Packages collection. (Subscribing really just means that the URL
+is added to the file `~/.nix-channels`, where it is read by subsequent
+calls to `nix-channel
+--update`.) You can “unsubscribe” using `nix-channel
+--remove`:
+
+```console
+$ nix-channel --remove nixpkgs
+```
+
+To obtain the latest Nix expressions available in a channel, do
+
+```console
+$ nix-channel --update
+```
+
+This downloads and unpacks the Nix expressions in every channel
+(downloaded from `url/nixexprs.tar.bz2`). It also makes the union of
+each channel’s Nix expressions available by default to `nix-env`
+operations (via the symlink `~/.nix-defexpr/channels`). Consequently,
+you can then say
+
+```console
+$ nix-env -u
+```
+
+to upgrade all packages in your profile to the latest versions available
+in the subscribed channels.

doc/manual/src/package-management/copy-closure.md

@@ -15,7 +15,7 @@ With `nix-store
 path (that is, the path and all its dependencies) to a file, and then
 unpack that file into another Nix store. For example,
 
-    $ nix-store --export $(nix-store --query --requisites $(type -p firefox)) > firefox.closure
+    $ nix-store --export $(nix-store -qR $(type -p firefox)) > firefox.closure
 
 writes the closure of Firefox to a file. You can then copy this file to
 another machine and install the closure:
@@ -27,7 +27,7 @@ store are ignored. It is also possible to pipe the export into another
 command, e.g. to copy and install a closure directly to/on another
 machine:
 
-    $ nix-store --export $(nix-store --query --requisites $(type -p firefox)) | bzip2 | \
+    $ nix-store --export $(nix-store -qR $(type -p firefox)) | bzip2 | \
         ssh alice@itchy.example.org "bunzip2 | nix-store --import"
 
 However, `nix-copy-closure` is generally more efficient because it only

doc/manual/src/package-management/profiles.md

@@ -39,7 +39,7 @@ just Subversion 1.1.2 (arrows in the figure indicate symlinks). This
 would be what we would obtain if we had done
 
 ```console
-$ nix-env --install --attr nixpkgs.subversion
+$ nix-env -iA nixpkgs.subversion
 ```
 
 on a set of Nix expressions that contained Subversion 1.1.2.
@@ -54,7 +54,7 @@ environment is generated based on the current one. For instance,
 generation 43 was created from generation 42 when we did
 
 ```console
-$ nix-env --install --attr nixpkgs.subversion nixpkgs.firefox
+$ nix-env -iA nixpkgs.subversion nixpkgs.firefox
 ```
 
 on a set of Nix expressions that contained Firefox and a new version of
@@ -127,7 +127,7 @@ All `nix-env` operations work on the profile pointed to by
 (abbreviation `-p`):
 
 ```console
-$ nix-env --profile /nix/var/nix/profiles/other-profile --install --attr nixpkgs.subversion
+$ nix-env -p /nix/var/nix/profiles/other-profile -iA nixpkgs.subversion
 ```
 
 This will *not* change the `~/.nix-profile` symlink.

doc/manual/src/package-management/ssh-substituter.md

@@ -6,7 +6,7 @@ automatically fetching any store paths in Firefox’s closure if they are
 available on the server `avalon`:
 
 ```console
-$ nix-env --install --attr nixpkgs.firefox --substituters ssh://alice@avalon
+$ nix-env -iA nixpkgs.firefox --substituters ssh://alice@avalon
 ```
 
 This works similar to the binary cache substituter that Nix usually
@@ -25,7 +25,7 @@ You can also copy the closure of some store path, without installing it
 into your profile, e.g.
 
 ```console
-$ nix-store --realise /nix/store/m85bxg…-firefox-34.0.5 --substituters
+$ nix-store -r /nix/store/m85bxg…-firefox-34.0.5 --substituters
 ssh://alice@avalon
 ```
 

doc/manual/src/protocols/derivation-aterm.md

@@ -1,19 +0,0 @@
-# Derivation "ATerm" file format
-
-For historical reasons, [derivations](@docroot@/glossary.md#gloss-store-derivation) are stored on-disk in [ATerm](https://homepages.cwi.nl/~daybuild/daily-books/technology/aterm-guide/aterm-guide.html) format.
-
-Derivations are serialised in one of the following formats:
-
-- ```
-  Derive(...)
-  ```
-
-  For all stable derivations.
-
-- ```
-  DrvWithVersion(<version-string>, ...)
-  ```
-
-  The only `version-string`s that are in use today are for [experimental features](@docroot@/contributing/experimental-features.md):
-
-  - `"xp-dyn-drv"` for the [`dynamic-derivations`](@docroot@/contributing/experimental-features.md#xp-feature-dynamic-derivations) experimental feature.

doc/manual/src/protocols/protocols.md

@@ -1,4 +0,0 @@
-# Protocols
-
-This chapter documents various developer-facing interfaces provided by
-Nix.

doc/manual/src/protocols/tarball-fetcher.md

@@ -1,42 +0,0 @@
-# Lockable HTTP Tarball Protocol
-
-Tarball flakes can be served as regular tarballs via HTTP or the file
-system (for `file://` URLs). Unless the server implements the Lockable
-HTTP Tarball protocol, it is the responsibility of the user to make sure that
-the URL always produces the same tarball contents.
-
-An HTTP server can return an "immutable" HTTP URL appropriate for lock
-files. This allows users to specify a tarball flake input in
-`flake.nix` that requests the latest version of a flake
-(e.g. `https://example.org/hello/latest.tar.gz`), while `flake.lock`
-will record a URL whose contents will not change
-(e.g. `https://example.org/hello/<revision>.tar.gz`). To do so, the
-server must return an [HTTP `Link` header](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Link) with the `rel` attribute set to
-`immutable`, as follows:
-
-```
-Link: <flakeref>; rel="immutable"
-```
-
-(Note the required `<` and `>` characters around *flakeref*.)
-
-*flakeref* must be a tarball flakeref. It can contain the tarball flake attributes
-`narHash`, `rev`, `revCount` and `lastModified`. If `narHash` is included, its
-value must be the NAR hash of the unpacked tarball (as computed via
-`nix hash path`). Nix checks the contents of the returned tarball
-against the `narHash` attribute. The `rev` and `revCount` attributes
-are useful when the tarball flake is a mirror of a fetcher type that
-has those attributes, such as Git or GitHub. They are not checked by
-Nix.
-
-```
-Link: <https://example.org/hello/442793d9ec0584f6a6e82fa253850c8085bb150a.tar.gz
-  ?rev=442793d9ec0584f6a6e82fa253850c8085bb150a
-  &revCount=835
-  &narHash=sha256-GUm8Uh/U74zFCwkvt9Mri4DSM%2BmHj3tYhXUkYpiv31M%3D>; rel="immutable"
-```
-
-(The linebreaks in this example are for clarity and must not be included in the actual response.)
-
-For tarball flakes, the value of the `lastModified` flake attribute is
-defined as the timestamp of the newest file inside the tarball.

doc/manual/src/quick-start.md

@@ -19,7 +19,7 @@ to subsequent chapters.
    channel:
 
    ```console
-   $ nix-env --query --available --attr-path
+   $ nix-env -qaP
    nixpkgs.docbook_xml_dtd_43                    docbook-xml-4.3
    nixpkgs.docbook_xml_dtd_45                    docbook-xml-4.5
    nixpkgs.firefox                               firefox-33.0.2
@@ -31,7 +31,7 @@ to subsequent chapters.
 1. Install some packages from the channel:
 
    ```console
-   $ nix-env --install --attr nixpkgs.hello
+   $ nix-env -iA nixpkgs.hello
    ```
 
    This should download pre-built packages; it should not build them
@@ -49,13 +49,13 @@ to subsequent chapters.
 1. Uninstall a package:
 
    ```console
-   $ nix-env --uninstall hello
+   $ nix-env -e hello
    ```
 
 1. You can also test a package without installing it:
 
    ```console
-   $ nix-shell --packages hello
+   $ nix-shell -p hello
    ```
 
    This builds or downloads GNU Hello and its dependencies, then drops
@@ -76,7 +76,7 @@ to subsequent chapters.
 
    ```console
    $ nix-channel --update nixpkgs
-   $ nix-env --upgrade '*'
+   $ nix-env -u '*'
    ```
 
    The latter command will upgrade each installed package for which
@@ -95,5 +95,5 @@ to subsequent chapters.
    them:
 
    ```console
-   $ nix-collect-garbage --delete-old
+   $ nix-collect-garbage -d
    ```

doc/manual/src/release-notes/rl-2.16.md

@@ -1,8 +0,0 @@
-# Release 2.16 (2023-05-31)
-
-* Speed-up of downloads from binary caches.
-  The number of parallel downloads (also known as substitutions) has been separated from the [`--max-jobs` setting](../command-ref/conf-file.md#conf-max-jobs).
-  The new setting is called [`max-substitution-jobs`](../command-ref/conf-file.md#conf-max-substitution-jobs).
-  The number of parallel downloads is now set to 16 by default (previously, the default was 1 due to the coupling to build jobs).
-
-* The function [`builtins.replaceStrings`](@docroot@/language/builtins.md#builtins-replaceStrings) is now lazy in the value of its second argument `to`. That is, `to` is only evaluated when its corresponding pattern in `from` is matched in the string `s`.

doc/manual/src/release-notes/rl-2.17.md

@@ -1,42 +0,0 @@
-# Release 2.17 (2023-07-24)
-
-* [`nix-channel`](../command-ref/nix-channel.md) now supports a `--list-generations` subcommand.
-
-* The function [`builtins.fetchClosure`](../language/builtins.md#builtins-fetchClosure) can now fetch input-addressed paths in [pure evaluation mode](../command-ref/conf-file.md#conf-pure-eval), as those are not impure.
-
-* Nix now allows unprivileged/[`allowed-users`](../command-ref/conf-file.md#conf-allowed-users) to sign paths.
-  Previously, only [`trusted-users`](../command-ref/conf-file.md#conf-trusted-users) users could sign paths.
-
-* Nested dynamic attributes are now merged correctly by the parser. For example:
-
-  ```nix
-  {
-    nested = {
-      foo = 1;
-    };
-    nested = {
-      ${"ba" + "r"} = 2;
-    };
-  }
-  ```
-
-  This used to silently discard `nested.bar`, but now behaves as one would expect and evaluates to:
-
-  ```nix
-  { nested = { bar = 2; foo = 1; }; }
-  ```
-
-  Note that the feature of merging multiple *full declarations* of attribute sets like `nested` in the example is of questionable value.
-  It allows writing expressions that are very hard to read, for instance when there are many lines of code between two declarations of the same attribute.
-  This has been around for a long time and is therefore supported for backwards compatibility, but should not be relied upon.
-
-  Instead, consider using the *nested attribute path* syntax:
-
-  ```nix
-  {
-    nested.foo = 1;
-    nested.${"ba" + "r"} = 2;
-  }
-  ```
-
-* Tarball flakes can now redirect to an "immutable" URL that will be recorded in lock files. This allows the use of "mutable" tarball URLs like `https://example.org/hello/latest.tar.gz` in flakes. See the [tarball fetcher](../protocols/tarball-fetcher.md) for details.

doc/manual/src/release-notes/rl-2.18.md

@@ -1,28 +0,0 @@
-# Release 2.18 (2023-09-20)
-
-- Two new builtin functions,
-  [`builtins.parseFlakeRef`](@docroot@/language/builtins.md#builtins-parseFlakeRef)
-  and
-  [`builtins.flakeRefToString`](@docroot@/language/builtins.md#builtins-flakeRefToString),
-  have been added.
-  These functions are useful for converting between flake references encoded as attribute sets and URLs.
-
-- [`builtins.toJSON`](@docroot@/language/builtins.md#builtins-parseFlakeRef) now prints [--show-trace](@docroot@/command-ref/conf-file.html#conf-show-trace) items for the path in which it finds an evaluation error.
-
-- Error messages regarding malformed input to [`nix derivation add`](@docroot@/command-ref/new-cli/nix3-derivation-add.md) are now clearer and more detailed.
-
-- The `discard-references` feature has been stabilized.
-  This means that the
-  [unsafeDiscardReferences](@docroot@/contributing/experimental-features.md#xp-feature-discard-references)
-  attribute is no longer guarded by an experimental flag and can be used
-  freely.
-
-- The JSON output for derived paths which are store paths is now a string, not an object with a single `path` field.
-  This only affects `nix-build --json` when "building" non-derivation things like fetched sources, which is a no-op.
-
-- A new builtin [`outputOf`](@docroot@/language/builtins.md#builtins-outputOf) has been added.
-  It is part of the [`dynamic-derivations`](@docroot@/contributing/experimental-features.md#xp-feature-dynamic-derivations) experimental feature.
-
-- Flake follow paths at depths greater than 2 are now handled correctly, preventing "follows a non-existent input" errors.
-
-- [`nix-store --query`](@docroot@/command-ref/nix-store/query.md) gained a new type of query: `--valid-derivers`. It returns all `.drv` files in the local store that *can be* used to build the output passed in argument. This is in contrast to `--deriver`, which returns the single `.drv` file that *was actually* used to build the output passed in argument. In case the output was substituted from a binary cache, this `.drv` file may only exist on said binary cache and not locally.

doc/manual/src/release-notes/rl-next.md

@@ -1,9 +1,2 @@
 # Release X.Y (202?-??-??)
 
-- Fix a FOD sandbox escape:
-    Cooperating Nix derivations could send file descriptors to files in the Nix
-    store to each other via Unix domain sockets in the abstract namespace. This
-    allowed one derivation to modify the output of the other derivation, after Nix
-    has registered the path as "valid" and immutable in the Nix database.
-    In particular, this allowed the output of fixed-output derivations to be
-    modified from their expected content. This isn't the case any more.

doc/manual/utils.nix

@@ -42,40 +42,20 @@ rec {
   filterAttrs = pred: set:
     listToAttrs (concatMap (name: let v = set.${name}; in if pred name v then [(nameValuePair name v)] else []) (attrNames set));
 
-  optionalString = cond: string: if cond then string else "";
-
-  showSetting = { inlineHTML }: name: { description, documentDefault, defaultValue, aliases, value, experimentalFeature }:
+  showSetting = { useAnchors }: name: { description, documentDefault, defaultValue, aliases, value }:
     let
       result = squash ''
-          - ${if inlineHTML
+          - ${if useAnchors
               then ''<span id="conf-${name}">[`${name}`](#conf-${name})</span>''
               else ''`${name}`''}
 
           ${indent "  " body}
         '';
 
-      experimentalFeatureNote = optionalString (experimentalFeature != null) ''
-          > **Warning**
-          > This setting is part of an
-          > [experimental feature](@docroot@/contributing/experimental-features.md).
-
-          To change this setting, you need to make sure the corresponding experimental feature,
-          [`${experimentalFeature}`](@docroot@/contributing/experimental-features.md#xp-feature-${experimentalFeature}),
-          is enabled.
-          For example, include the following in [`nix.conf`](#):
-
-          ```
-          extra-experimental-features = ${experimentalFeature}
-          ${name} = ...
-          ```
-        '';
-
       # separate body to cleanly handle indentation
       body = ''
           ${description}
 
-          ${experimentalFeatureNote}
-
           **Default:** ${showDefault documentDefault defaultValue}
 
           ${showAliases aliases}
@@ -94,7 +74,7 @@ rec {
         else "*machine-specific*";
 
       showAliases = aliases:
-          optionalString (aliases != [])
+          if aliases == [] then "" else
             "**Deprecated alias:** ${(concatStringsSep ", " (map (s: "`${s}`") aliases))}";
 
     in result;

docker.nix

@@ -190,12 +190,6 @@ let
         cp -a ${rootEnv}/* $out/
         ln -s ${manifest} $out/manifest.nix
       '';
-      flake-registry-path = if (flake-registry == null) then
-        null
-      else if (builtins.readFileType (toString flake-registry)) == "directory" then
-        "${flake-registry}/flake-registry.json"
-      else
-        flake-registry;
     in
     pkgs.runCommand "base-system"
       {
@@ -208,7 +202,7 @@ let
         ];
         allowSubstitutes = false;
         preferLocalBuild = true;
-      } (''
+      } ''
       env
       set -x
       mkdir -p $out/etc
@@ -255,15 +249,15 @@ let
       ln -s ${pkgs.coreutils}/bin/env $out/usr/bin/env
       ln -s ${pkgs.bashInteractive}/bin/bash $out/bin/sh
 
-    '' + (lib.optionalString (flake-registry-path != null) ''
+    '' + (lib.optionalString (flake-registry != null) ''
       nixCacheDir="/root/.cache/nix"
       mkdir -p $out$nixCacheDir
       globalFlakeRegistryPath="$nixCacheDir/flake-registry.json"
-      ln -s ${flake-registry-path} $out$globalFlakeRegistryPath
+      ln -s ${flake-registry}/flake-registry.json $out$globalFlakeRegistryPath
       mkdir -p $out/nix/var/nix/gcroots/auto
       rootName=$(${pkgs.nix}/bin/nix --extra-experimental-features nix-command hash file --type sha1 --base32 <(echo -n $globalFlakeRegistryPath))
       ln -s $globalFlakeRegistryPath $out/nix/var/nix/gcroots/auto/$rootName
-    ''));
+    '');
 
 in
 pkgs.dockerTools.buildLayeredImageWithNixDb {