* It is tough to contribute to a project that doesn't use a formatter,
* It is extra hard to contribute to a project which has configured the formatter, but ignores it for some files
* Code formatting makes it harder to hide obscure / weird bugs by accident or on purpose,
Let's rip the bandaid off?
Note that PRs currently in flight should be able to be merged relatively easily by applying `clang-format` to their tip prior to merge.
Previously, `nix help shell` failed with "Nix has no subcommand 'shell'" despite `nix shell --help`
working correctly. This happened because the `shell` command is actually an alias for `env shell`,
and the help system wasn't resolving aliases when looking up documentation.
This patch modifies the `showHelp` function to check for and resolve aliases before generating the
manpage name, ensuring that shorthand commands like `shell` get proper help documentation.
Closes: #13431
Move init() call from constructor to openStore() method to avoid calling
virtual methods during object construction. This prevents undefined
behavior when virtual methods are called before the object is fully
constructed.
Move init() call from constructor to openStore() method to avoid calling
virtual methods during object construction. This prevents undefined
behavior when virtual methods are called before the object is fully
constructed.
When `file://` is used accidentally in a flake as the source it is
expected to be a tarball by default.
Add some friendlier error messages to either inform the user this is not
in fact a tarball or if it's a git directory, let them know they can use
`git+file`.
fixes#12935
Users have complained that fetchGit is flaky however the culprit is
likely that `git fetch` was unable itself to download the repository for
whatever reason (i.e. poor network etc..)
Nothing was checking the status of `git fetch` and the error message
that would eventually surface to the users were that the commit was not
found.
Add explicit error checking for status code from `git fetch` and return
a message earlier on to indicate that the failure was from that point.
fixes#10431
We’re already allowing `/tmp` anyway, so this should be harmless,
and it fixes a regression in the default configuration caused by
moving the build directories out of `temp-dir`. (For instance, that
broke the Lix `guessOrInventPath.sockets` test.)
Note that removing `/tmp` breaks quite a few builds, so although it may
be a good idea in general it would require work on the Nixpkgs side.
Fixes: 749afbbe99fd7b45f828b72628252feba9241362
Change-Id: I6a6a69645f429bc50d4cb24283feda3d3091f534
(This is a cherry-pick of commit d1db3e5fa3faa43b3d2f2e2e843e9cfc1e6e1b71)
Lix patch: https://gerrit.lix.systems/c/lix/+/3500
When AWS credentials expired, in some scenarios they led to the
nix process aborting with an error similar to ' Unable to parse ExceptionName: ExpiredToken'.
This change updates the S3 handling code such that those errors are treated like 403s or 404s.
Closes#13459
c39cc00404 has added assertions for
all Value accesses and the following case has started failing with
an `unreachable`:
(/tmp/fun.nix):
```nix
{a}: a
```
```
$ nix eval --impure --expr 'import /tmp/fun.nix {a="a";b="b";}'
```
This would crash:
```
terminating due to unexpected unrecoverable internal error: Unexpected condition in getStorage at ../include/nix/expr/value.hh:844
```
This is not a regression, but rather surfaces an existing problem, which previously
was left undiagnosed. In the case of an import `fun` is the `import` primOp, so that read is invalid
and previously this resulted in an access into an inactive union member, which is UB.
The correct thing to use is `vCur`. Identical problem also affected the case of a missing argument.
Add previously failing test cases to the functional/lang test suite.
Fixes#13448.
Fixes:
[261/394] Linking target src/libexpr/libnixexpr.so
In function ‘copy’,
inlined from ‘__ct ’ at /nix/store/24sdvjs6rfqs69d21gdn437mb3vc0svh-gcc-14.2.1.20250322/include/c++/14.2.1.20250322/bits/basic_string.h:688:23,
inlined from ‘operator+’ at /nix/store/24sdvjs6rfqs69d21gdn437mb3vc0svh-gcc-14.2.1.20250322/include/c++/14.2.1.20250322/bits/basic_string.h:3735:43,
inlined from ‘operator()’ at ../src/libexpr/primops/fetchClosure.cc:127:58,
inlined from ‘prim_fetchClosure’ at ../src/libexpr/primops/fetchClosure.cc:132:88:
/nix/store/24sdvjs6rfqs69d21gdn437mb3vc0svh-gcc-14.2.1.20250322/include/c++/14.2.1.20250322/bits/char_traits.h:427:56: warning: ‘__builtin_memcpy’ writing 74 bytes into a region of size 16 overflows the destination [-Wstringop-overflow=]
427 | return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n));
| ^
../src/libexpr/primops/fetchClosure.cc: In function ‘prim_fetchClosure’:
../src/libexpr/primops/fetchClosure.cc:132:88: note: at offset 16 into destination object ‘<anonymous>’ of size 32
132 | fromPath = state.coerceToStorePath(attr.pos, *attr.value, context, attrHint());
| ^
-p preserves xattrs and acls which can be incompatible between
filesystems
Unfortunately keep -p on darwin because the bsd coreutils do not
support --preserve.
Fixes#13426
This failed on macOS:
nix-store-tests-run> C++ exception with description "../nix_api_store.cc:33: nix_err_code(ctx) != NIX_OK, message: error: getting status of '/nix/var/nix/daemon-socket/socket': Operation not permitted" thrown in the test body.
This changes makes nix detect a machines available cores automatically whenever build-cores is set to 0.
So far, nix simply passed NIX_BUILD_CORES=0 whenever build-cores is set to 0. (only when build-cores is unset it was detecting cores automatically)
The behavior of passing NIX_BUILD_CORES=0 leads to a performance penalty when sourcing nixpkgs' generic builder's `setup.sh`, as setup.sh has to execute `nproc`. This significantly slows down sourcing of setup.sh
The use of R"(...)" added a bunch of unnecessary whitespace, e.g.
error:
Unable to start any build;
either increase '--max-jobs' or enable remote builds.
For more information run 'man nix.conf' and search for '/machines'.
Now we get
error: Unable to start any build; either increase '--max-jobs' or enable remote builds.
For more information run 'man nix.conf' and search for '/machines'.
This shaves off a very significand amount of memory used
for evaluation as well as reduces the GC-managed heap.
Previously the union discriminator (InternalType) was
stored as a separate field in the Value, which takes up
whole 8 bytes due to padding needed for member alignment.
This effectively wasted 7 whole bytes of memory. Instead
of doing that InternalType is instead packed into pointer
alignment niches. As it turns out, there's more than enough
unused bits there for the bit packing to be effective.
See the doxygen comment in the ValueStorage specialization
for more details.
This does not add any performance overhead, even though
we now consistently assert the InternalType in all getters.
This can also be made atomic with a double width compare-and-swap
instruction on x86_64 (CMPXCHG16B instruction) for parallel evaluation.
This factors out most of the value representation into a mixin class.
`finishValue` is now gone for good and replaced with a simple template
function `setStorage` which derives the type information/disriminator from
the type of the argument. Likewise, reading of the value goes through function
template `getStorage`.
An empty type `Null` is introduced to make the bijection InternalType <-> C++ type
complete.
Previous use of symlink_status() always translated into a stat call, leading
to huge performance penalties for by-name-overlay in nixpkgs. The comment
below references the possible caching, but that seemed to be erroneous, since
the correct way to make use of the caching API is by calling a bunch of `is_*`
functions [1]. For example, here's how libstdc++ does that [2], [3].
This translates to great nixpkgs eval performance improvements:
```
Benchmark 1: GC_INITIAL_HEAP_SIZE=4G result/bin/nix-instantiate ../nixpkgs -A hello --readonly-mode
Time (mean ± σ): 186.7 ms ± 6.7 ms [User: 121.3 ms, System: 64.9 ms]
Range (min … max): 179.4 ms … 201.6 ms 16 runs
Benchmark 2: GC_INITIAL_HEAP_SIZE=4G nix-instantiate ../nixpkgs -A hello --readonly-mode
Time (mean ± σ): 230.6 ms ± 5.0 ms [User: 126.9 ms, System: 103.1 ms]
Range (min … max): 225.1 ms … 241.4 ms 13 runs
```
[1]: https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0317r1.html
[2]: 8ea555b7b4/libstdc%2B%2B-v3/include/bits/fs_dir.h (L341-L348)
[3]: 8ea555b7b4/libstdc%2B%2B-v3/include/bits/fs_dir.h (L161-L163)
These wrappers don't seem to be used anywhere in and out of tree.
Also the declaration in the header has an incorrect function name `maybeParseFlake`.
Closes#11948
Fixes
error:
… while processing sandbox path '/private/tmp/nix-shell.0MDgyx/nix-test/ca/repl/store/nix/var/nix/builds/nix-build-simple.drv-65916-3910734210' (/private/tmp/nix-shell.0MDgyx/nix-test/ca/repl/store)
error: 'nix' is too short to be a valid store path
which happened because we were now putting the build directory
underneath the store directory.
If a build directory is accessible to other users it is possible to
smuggle data in and out of build directories. Usually this is only
a build purity problem, but in combination with other issues it can
be used to break out of a build sandbox. to prevent this we default
to using a subdirectory of nixStateDir (which is more restrictive).
(cherry picked from pennae Lix commit 55b416f6897fb0d8a9315a530a9b7f0914458ded)
(store setting done by roberth)
In the case the deletion fails, we should ensure that the temporary
directory cannot be used for nefarious purposes.
Change-Id: I498a2dd0999a74195d13642f44a5de1e69d46120
Signed-off-by: Raito Bezarius <raito@lix.systems>
When calling `_deletePath` with a parent file descriptor, `openat` is
made effective by using relative paths to the directory file descriptor.
To avoid the problem, the signature is changed to resist misuse with an
assert in the prologue of the function.
Change-Id: I6b3fc766bad2afe54dc27d47d1df3873e188de96
Signed-off-by: Raito Bezarius <raito@lix.systems>
This ensures that `passAsFile` data is created inside the expected
temporary build directory by `openat()` from the parent directory file
descriptor.
This avoids a TOCTOU which is part of the attack chain of CVE-????.
Change-Id: Ie5273446c4a19403088d0389ae8e3f473af8879a
Signed-off-by: Raito Bezarius <raito@lix.systems>
`writeFile` lose its `sync` boolean flag to make things simpler.
A new `writeFileAndSync` function is created and all call sites are
converted to it.
Change-Id: Ib871a5283a9c047db1e4fe48a241506e4aab9192
Signed-off-by: Raito Bezarius <raito@lix.systems>
We use it immediately for the build temporary directory.
Change-Id: I180193c63a2b98721f5fb8e542c4e39c099bb947
Signed-off-by: Raito Bezarius <raito@lix.systems>
We now keep around a proper AutoCloseFD around the temporary directory
which we plan to use for openat operations and avoiding the build
directory being swapped out while we are doing something else.
Change-Id: I18d387b0f123ebf2d20c6405cd47ebadc5505f2a
Signed-off-by: Raito Bezarius <raito@lix.systems>
This is useful for certain error recovery paths (no pun intended) that
does not thread through the original path name.
Change-Id: I2d800740cb4f9912e64c923120d3f977c58ccb7e
Signed-off-by: Raito Bezarius <raito@lix.systems>
This is just a code cleanup; it should not be behavior change.
`addWantedOutputs` is removed by introducing `DerivationTrampolineGoal`.
`DerivationGoal` now only tracks a single output, and is back to
tracking a plain store path `drvPath`, not a deriving path one. Its
`addWantedOutputs` method is gone. These changes will allow subsequent
PRs to simplify it greatly.
Because the purpose of each goal is back to being immutable, we can also
once again make `Goal::buildResult` a public field, and get rid of the
`getBuildResult` method. This simplifies things also.
`DerivationTrampolineGoal` is, as the nane is supposed to indicate, a
cheap "trampoline" goal. It takes immutable sets of wanted outputs, and
just kicks of `DerivationGoal`s for them. Since now "actual work" is
done in these goals, it is not wasteful to have separate ones for
separate sets of outputs, even if those outputs (and the derivations
they are from) overlap.
This design is described in more detail in the doc comments on the goal
types, which I've now greatly expanded.
---
This separation of concerns will make it possible for future work on
issues like #11928, and to continue the path of having more goal types,
but each goal type does fewer things (issue #12628).
---
This commit in some sense reverts
f4f28cdd0e, but that one kept around
`addWantedOutputs`. I am quite sure it was having two layers of goals
with `addWantedOutputs` that caused the issues --- restarting logic like
`addWantedOutputs` has is very tempermental! In this version of the
change, we have *zero* layers of `addWantedOutputs` --- no goal type
needs it, or otherwise has a mutable objective --- and so I think this
change is safe.
Co-authored-by: Sergei Zimmerman <145775305+xokdvium@users.noreply.github.com>
Running parallel nix in nix can lead to multiple instances trying to
create the state directories and failing on the `createSymlink` step,
because the link already exists.
`replaceSymlink` is already idempotent, so let's use that.
Resolves#2706
libstdc++'s std::stable_sort and new builtins.sort implementation
special-case ranges with length less than or equal to 16 and delegate
to insertionsort.
Having a larger e2e test would allow catching sort stability issues
at functional level as well.
This prevents C++ level undefined behavior from affecting
the evaluator. Stdlib implementation details should not affect
eval, regardless of the build platform. Even erroneous usage
of `builtins.sort` should not make it possible to crash the
evaluator or produce results that depend on the host platform.
Unlike std::sort and std::stable_sort, this implementation
does not lead to out-of-bounds memory reads or other undefined
behavior when the predicate is not strict weak ordering.
This makes it possible to use this function in libexpr for
builtins.sort, where an incorrectly implemented comparator
in the user nix code currently can crash and burn the evaluator
by invoking C++ UB.
Makes the behavoral change of #13263 without the underlying refactor.
Hopefully this clearly safe from a perf and GC perspective, and will
make it easier to benchmark #13263.
This overload isn't actually necessary anywhere and
doesn't make much sense. The pointers to `Value`s are
themselves const, but the `Value`s are mutable.
A non-const member function implies that the object itself
can be modified but this doesn't make much sense considering
the return type: `Value * const * `, which is a pointer
to a constant array of pointers to mutable values.
It seems obvious that erasing any output paths from pathsInChroot needs
to happen after getPathsInSandbox(), not before.
Signed-off-by: Samuli Thomasson <samuli.thomasson@pm.me>
This adds a meson.format file that mostly mirrors the projects
meson style and a pre-commit hook to enforce this style.
Some low-diff files are formatted.
Seen in https://github.com/DeterminateSystems/nix-src/actions/runs/15590867877/job/43909540271:
nix-functional-tests> grep: repl_output: No such file or directory
nix-functional-tests> +(repl.sh:174) cat repl_output
This is because there is a small possibility that the `nix repl` child
process hasn't created `repl_output` yet. So make sure it exists.
Invoking `:ll` will start a pager with all variables which have just
been loaded by `:lf`, `:l`, or by a flake provided to `nix repl` as an
argument.
https://github.com/NixOS/nix/issues/11404
When we run `nix repl nixpkgs` we get "Added 6 variables". This is not
useful as it doesn't tell us which variables the flake has exported to
our global repl scope.
This patch prints the name of each variable that was just loaded. We
currently cap printing to 20 variables in order to avoid excessive
prints.
https://github.com/NixOS/nix/issues/11404
`getPrimOp` function was basically identical to existing
`Value::primOpAppPrimOp` modulo some trivial differences.
Makes sense to reuse existing code for that.
There's actually no mutation happening so there's no point in using
a mutable shared_ptr. Furthermore, this makes it much more evident to
the reader that no actual mutation (especially in multithreaded case)
is happening.
Also get rid of redundant constructor that isn't actually used anywhere
other than `Pos::operator std::shared_ptr<Pos>` which just passes in &*this,
(identical to just `this`), which can't be nullptr.
Judging by the comment for `makeEmptySourceAccessor` the prefix has
to be empty:
> Return a source accessor that contains only an empty root directory.
Fixes#13295.
Since the migration to meson precompiled-headers.h isn't actually used
anymore and is just confusing. Meson can't handle shared pch across
subprojects [1] and without that there's no performances benefit of PCH
at all. Also rolling our own support for that isn't trivial. See [2] for
an example of how that would look like.
[1]: https://github.com/mesonbuild/meson/issues/4350
[2]: 22bc8b6473/plugins/meson.build
Clang doesn't like the double indent that is needed for the `if...else`
that is CPP'd away. Adding braces is fine in the `if...else...` case,
and fine as a naked block in the CPP'd away case, and properly-indented
both ways.
These tests have been collected from nixpkgs f870c6ccc8951fc48aeb293cf3e98ade6ac42668
usage of builtins.match for x86_64-linux eval system. At most 2 matching and
non-matching cases are included for each encountered regex. This should
hopefully add more confidence when possibly trying to switch the regex implementation
in the future.
This is the utility changes from #9968, which were easier to rebase
first.
I (@Ericson2314) didn't write this code; I just rebased it.
Co-Authored-By: Artemis Tosini <me@artem.ist>
Co-Authored-By: Audrey Dutcher <audrey@rhelmot.io>
Allows to copy the archive to a remote host and not get
error: cannot add path '/nix/store/01x2k4nlxcpyd85nnr0b9gm89rm8ff4x-source' because it lacks a signature by a trusted key
Before we got something like this but only inside the VM test:
vm-test-run-functional-tests-on-nixos_user> machine # fetchGit.sh: line 286: unexpected EOF while looking for matching `)'
We now try to do not too much in a single line, so that the bash parser does not get confused.
This also seems more readable and better quoted.
This makes the profiler much more useful by actually distiguishing
different derivations being evaluated. This does make the implementation
a bit more convoluted, but I think it's worth it.
Sometimes the profiler might want to do evaluation (e.g. for getting
derivation names). This is not ideal, but is really necessary
to make the profiler stack traces useful for end users.
...and also NIX_STATE_HOME in nix-profile.fish. This is directly
translated from the bash scripts and makes the fish scripts equivalent
in functionality to the bash scripts.
Note that nix-profile.fish checks for NIX_STATE_HOME and
nix-profile-daemon.fish does not, so the two scripts are no longer
identical.
This was discussed in https://github.com/NixOS/nix/issues/8034. I
personally like `PRJ_ROOT`, which hopefully avoids some ambiguity
around with subflakes.
I only implemented this for `nix fmt` because it doesn't let you point
at a flake not on your filesystem.
macOS compilation fixes
This method does *not* create a new type of goal. We instead just make
`DerivationGoal` more sophisticated, which is much easier to do now that
`DerivationBuildingGoal` has been split from it (and so many fields are
gone, or or local variables instead).
This avoids the need for a secondarily trampoline goal that interacted
poorly with `addWantedOutputs`. That, I hope, will mean the bugs from
before do not reappear.
There may in fact be a reason to introduce such a trampoline in the
future, but it would only happen in conjunction with getting rid of
`addWantedOutputs`.
Restores the functionality (and tests) that was reverted in
f4f28cdd0e.
This patch adds support for a native stack sampling
profiler to the evaluator, which saves a collapsed stack
profile information to a configurable location.
Introduced options (in `EvalSettings`):
- `eval-profile-file` - path to the collected profile file.
- `eval-profiler-frequency` - sampling frequency.
- `eval-profiler` - enumeration option for enabling the profiler.
Currently only `flamegraph` is supported, but having this an
enumeration rather than a boolean switch leaves the door open
for other profiler variants (e.g. tracy).
Profile includes the following information on best-effort basis (e.g. some lambdas might
have an undefined name). Callstack information contains:
- Call site location (where the function gets called).
- Primop/lambda name of the function being called.
- Functors/partial applications don't have a name attached to them unlike special-cased primops and lambads.
For cases where callsite location isn't available we have to resort to providing
the location where the lambda itself is defined. This removes some of the confusing
`«none»:0` locations in the profile from previous attempts.
Example usage with piping directly into zstd for compression:
```
nix eval --no-eval-cache nixpkgs#nixosTests.gnome \
--eval-profiler flamegraph \
--eval-profile-file >(zstd -of nix.profile.zstd)
```
Co-authored-by: Jörg Thalheim <joerg@thalheim.io>
Commit b36637c8f7 set
`__ETC_PROFILE_NIX_SOURCED` globally, but this is not enough to prevent
the script from being run again by child shells, because the
variable was not exported and thus not inherited by any child process.
Exporting the variable also agrees with the bash scripts.
Notably, the old behavior broke `nix develop -c fish` in some cases,
because the profile bin directory got prepended to the path, causing
binaries from the profile to override binareis from the devshell.
This wires up the {pre,post}FunctionCallHook machinery
in EvalState::callFunction and migrates FunctionCallTrace
to use the new EvalProfiler mechanisms for tracing.
Note that branches when the hook gets called are marked with [[unlikely]]
as a hint to the compiler that this is not a hot path. For non-tracing
evaluation this should be a 100% predictable branch, so the performance
cost is nonexistent.
Some measurements to prove support this point:
```
nix build .#nix-cli
nix build github:nixos/nix/d692729759e4e370361cc5105fbeb0e33137ca9e#nix-cli --out-link before
```
(Before)
```
$ taskset -c 2,3 hyperfine "GC_INITIAL_HEAP_SIZE=16g before/bin/nix eval nixpkgs#gnome --no-eval-cache" --warmup 4
Benchmark 1: GC_INITIAL_HEAP_SIZE=16g before/bin/nix eval nixpkgs#gnome --no-eval-cache
Time (mean ± σ): 2.517 s ± 0.032 s [User: 1.464 s, System: 0.476 s]
Range (min … max): 2.464 s … 2.557 s 10 runs
```
(After)
```
$ taskset -c 2,3 hyperfine "GC_INITIAL_HEAP_SIZE=16g result/bin/nix eval nixpkgs#gnome --no-eval-cache" --warmup 4
Benchmark 1: GC_INITIAL_HEAP_SIZE=16g result/bin/nix eval nixpkgs#gnome --no-eval-cache
Time (mean ± σ): 2.499 s ± 0.022 s [User: 1.448 s, System: 0.478 s]
Range (min … max): 2.472 s … 2.537 s 10 runs
```
This patch adds an EvalProfiler and MultiEvalProfiler that can be used
to insert hooks into the evaluation for the purposes of function tracing
(what function-trace currently does) or for flamegraph/tracy profilers.
See the following commits for how this is supposed to be integrated into
the evaluator and performance considerations.
Ensure relative path inputs are relative to the parent node's _actual_
`outPath`, instead of the subtly different `sourceInfo.outPath`.
Additionally, non-flake inputs now also have a `sourceInfo` attribute.
This fixes the relationship between `self.outPath` and
`self.sourceInfo.outPath` in some edge cases.
Fixes#13164
Previous code had a sneaky bug due to which no caching
actually happened:
```cpp
auto linesForInput = (*lines)[origin->offset];
```
That should have been:
```cpp
auto & linesForInput = (*lines)[origin->offset];
```
See [1].
Now that it also makes sense to make the cache bound in side
in order not to memoize all the sources without freeing any memory.
The default cache size has been chosen somewhat arbitrarily to be ~64k
origins. For reference, 25.05 nixpkgs has ~50k .nix files.
Simple benchmark:
```nix
let
pkgs = import <nixpkgs> { };
in
builtins.foldl' (acc: el: acc + el.line) 0 (
builtins.genList (x: builtins.unsafeGetAttrPos "gcc" pkgs) 10000
)
```
(After)
```
$ hyperfine "result/bin/nix eval -f ./test.nix"
Benchmark 1: result/bin/nix eval -f ./test.nix
Time (mean ± σ): 292.7 ms ± 3.9 ms [User: 131.0 ms, System: 120.5 ms]
Range (min … max): 288.1 ms … 300.5 ms 10 runs
```
(Before)
```
hyperfine "nix eval -f ./test.nix"
Benchmark 1: nix eval -f ./test.nix
Time (mean ± σ): 666.7 ms ± 6.4 ms [User: 428.3 ms, System: 191.2 ms]
Range (min … max): 659.7 ms … 681.3 ms 10 runs
```
If the origin happens to be a `all-packages.nix` or similar in size then the
difference is much more dramatic.
[1]: 22e3f0e987
Try to make `DerivationGoal` care less whether we're working from an
in-memory derivation or not.
It's a clean-up in its own right, but it will also help with other
cleanups under the umbrella of #12628.
Now, each class provides the initial coroutine by value. This avoids
some sketchy virtual function stuff, and will also be further put to
good use in the next commit.
As summarized in
https://github.com/NixOS/nix/issues/77#issuecomment-2843228280 the
motivation is that the complicated retry logic this introduced was
making the cleanup task #12628 harder to accomplish. It was not easy to
ascertain just what policy / semantics the extra control-flow was
implementing, in order to figure out a different way to implementing it
either.
After talking to Eelco about it, he decided we could just....get rid of
the feature entirely! It's a bit scary removing a decade+ old feature,
but I think he is right. See the release notes for more explanation.
This reverts commit 299141ecbd.
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
Leverage #10766 to show how we can now resolve a store configuration
without actually opening the store for that resolved configuration.
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Splicing the list element to the back can be done in
a much simpler and concise way without the need for
erasing and re-inserting the element. Doing it this
way is equivalent to just moving node pointers around,
whereas inserting/erasing allocates/deallocates new nodes.
This renders the rl-next notes when `officialRelease = false`, which
corresponds to the case where we're not on a release branch.
Previously we had disabled this behavior because changelog-d is
somewhat of a heavy dependency, being the only Haskell package.
However, we now have new circumstances that topple the tradeoff.
- We render `master` docs to https://nix.dev/manual/nix/development/release-notes/rl-next.html
- `.#manual` is a separate build now, so `nix build nix/foo` is
not affected by the increased closure of build input outputs.
Because of these factors, I believe adding this functionality back
is more valuable, as we can use it to
- Previous release notes
- Showcase the upcoming release to the community
The existing header is a bit too big. Now the following use-cases are
separated, and get their own headers:
- Using or implementing an arbitrary store: remaining `store-api.hh`
This is closer to just being about the `Store` (and `StoreConfig`)
classes, as one would expect.
- Opening a store from a textual description: `store-open.hh`
Opening an aribtrary store implementation like this requires some sort
of store registration mechanism to exists, but the caller doesn't need
to know how it works. This just exposes the functions which use such a
mechanism, without exposing the mechanism itself
- Registering a store implementation: `store-registration.hh`
This requires understanding how the mechanism actually works, and the
mechanism in question involves templated machinery in headers we
rather not expose to things that don't need it, as it would slow down
compilation for no reason.
I can't find a good way to benchmark in isolation from the
git cache, but common sense dictates that creating (and destroying)
a 131KiB std::vector for each regular file from the archive imposes
quite a significant overhead regardless of the IO bound git cache.
AFAICT there is no reason to keep a copy of the data since
it always gets fed into the sink and there are no coroutines/threads
in sight.
warning: installing Nix as root is not supported by this script!
performing a single-user installation of Nix...
copying Nix to /nix/store.......................................................
......
warning: the group 'nixbld' specified in 'build-users-group' does not exist
warning: the group 'nixbld' specified in 'build-users-group' does not exist
installing 'nix-2.28.3'
error: the group 'nixbld' specified in 'build-users-group' does not exist
/tmp/nix-binary-tarball-unpack.2j3lCU0A89/unpack/nix-2.28.3-x86_64-linux/install: unable to install Nix into your default profile
The nixos/nix docker image is built using `buildLayeredImage`, which spreads the nix store over a configured number of layers. This number was set to create an image with 100 layers. Because there is a limit of (typically) 127 layers in AUFS, this only left 27 layers to build on top. At the same time, nearly half of the created layers were only <100kb in size, many even <10kb, negating the intended advantage in cachability.
This commit moves the tradeoff a bit by reducing the number of layers to 70.
Layer sizes for the 2.28.3 nixos/nix image: https://hub.docker.com/layers/nixos/nix/2.28.3/images/sha256-d078d7153763895fce17c5fbbdeb86fcfcac414ca0ba875d413c1df57be19931
As it turns out using `std::regex` is actually the bottleneck
for root discovery. Just substituting `std::` -> `boost::`
makes root discovery twice as fast (3x if counting only userspace time).
Some rather ad-hoc measurements to motivate the switch:
(On master)
```
nix build github:nixos/nix/1e822bd4149a8bce1da81ee2ad9404986b07914c#nix-cli --out-link result-1e822bd4149a8bce1da81ee2ad9404986b07914c
taskset -c 2,3 hyperfine "result-1e822bd4149a8bce1da81ee2ad9404986b07914c/bin/nix store gc --dry-run --max 0"
Benchmark 1: result-1e822bd4149a8bce1da81ee2ad9404986b07914c/bin/nix store gc --dry-run --max 0
Time (mean ± σ): 481.6 ms ± 3.9 ms [User: 336.2 ms, System: 142.0 ms]
Range (min … max): 474.6 ms … 487.7 ms 10 runs
```
(After this patch)
```
taskset -c 2,3 hyperfine "result/bin/nix store gc --dry-run --max 0"
Benchmark 1: result/bin/nix store gc --dry-run --max 0
Time (mean ± σ): 254.7 ms ± 9.7 ms [User: 111.1 ms, System: 141.3 ms]
Range (min … max): 246.5 ms … 281.3 ms 10 runs
```
`boost::regex` is a drop-in replacement for `std::regex`, but much faster.
Doing a simple before/after comparison doesn't surface any change in behavior:
```
result/bin/nix store gc --dry-run -vvvvv --max 0 |& grep "got additional" | wc -l
result-1e822bd4149a8bce1da81ee2ad9404986b07914c/bin/nix store gc --dry-run -vvvvv --max 0 |& grep "got additional" | wc -l
```
Remove outdated and no longer relevant TODO. It's more confusing
now, since symbol table must now be addressed by uint32_t indices
in order to keep Attr size down to 16 bytes on 64 bit machines.
This patch finally applies the transition to std::less<>,
which is a transparent comparator. There's no functional
change and string lookups in sets are now more efficient
and don't produce temporaries (e.g. set.find(std::string_view{"key"})).
Unfortunately Feature is just an alias to `std::string`
and not a new-type, so a ton of code relies on it being
exactly a `std::string`.
Using transparent comparators just for StringSet necessitates
using it here as well.
The intention is to switch to transparent comparators from N3657 for
ordered set containers for strings and using the alias consistently
would simplify things.
This trades off some executable size for measurable lexer performance
improvements.
Note on the explicitly enabling 8bit scanner.
This is needed due to the default behavior of flex (excerpt from the manual [1]):
> Flex’s default behavior is to generate an 8-bit scanner unless you
> use the ‘-Cf’ or ‘-CF’, in which case flex defaults to generating
> 7-bit scanners unless your site was always configured to generate 8-bit
> scanners.
Some quantifyable metrics:
Nixpkgs revision: a6e3f45acf4e817532a861ab0eda4ab5485fecc1
Parsing the largest file in nixpkgs: pkgs/development/haskell-modules/hackage-packages.nix.
(Before this patch)
```
$ nix build github:nixos/nix/9fe3077d4#nix-expr
$ du --apparent-size result/lib/libnixexpr.so
2518 result/lib/libnixexpr.so
$ nix build github:nixos/nix/9fe3077d4#nix-cli
$ taskset -c 2,3 hyperfine "GC_INITIAL_HEAP_SIZE=16g \
result/bin/nix-instantiate --parse \
../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix > /dev/null"
Time (mean ± σ): 375.5 ms ± 6.3 ms [User: 316.9 ms, System: 56.7 ms]
Range (min … max): 368.5 ms … 388.3 ms 10 runs
```
(After the patch)
```
$ nix build .#nix-expr
$ du --apparent-size result/lib/libnixexpr.so
2685 result/lib/libnixexpr.so
$ nix build .#nix-cli
$ taskset -c 2,3 hyperfine "GC_INITIAL_HEAP_SIZE=16g \
result/bin/nix-instantiate --parse \
../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix > /dev/null"
Time (mean ± σ): 326.8 ms ± 4.9 ms [User: 269.5 ms, System: 55.3 ms]
Range (min … max): 319.7 ms … 335.5 ms 10 runs
```
Overall, the change is roughly:
- 2518KiB -> 2685KiB ~ 150 KiB of machine code
- 375ms -> 325ms ~ 50ms
The perf uplift for eval-heavy test cases is obviously less noticeable,
but it doesn't make sense not to take this free perf win.
[1]: https://westes.github.io/flex/manual/Options-Affecting-Scanner-Behavior.html#Options-Affecting-Scanner-Behavior
When a PUT is redirected, some of the data can be sent by curl before headers are read. This means the subsequent PUT operation needs to seek back to origin.
The current example relies upon [nixfmt's deprecated tree traversal
behavior](https://github.com/NixOS/nixfmt/pull/240). The simplest
alternative is the new `nixfmt-tree` wrapper for `nixfmt`/`treefmt`.
Since we dropped fs::symlink_exists, we no longer have a need for the fs
namespace. Having less abstractions makes it easier to lookup the
functions in reference documentations.
As it turns out the orignal implementation of symlink_exists cannot be
used in Nix because it did now std::filesystem::filesystem_error.
The new implementation fixes that but is now actually the same as
pathExists except for the path type.
`nix formatter build` is sort of like `nix build`: it builds, links, and
prints a path to the formatter program:
$ nix formatter build
/nix/store/cb9w44vkhk2x4adfxwgdkkf5gjmm856j-treefmt/bin/treefmt
Note that unlike `nix build`, this prints the full path to the program,
not just the store path (in the example above that would be
`/nix/store/cb9w44vkhk2x4adfxwgdkkf5gjmm856j-treefmt`).
Motivation
----------
I maintain a vim plugin that automatically runs `nix fmt` on files on
save. Since `nix fmt` can be quite slow due to nix evaluation, I choose
to cache the `nix fmt `entrypoint. This was very awkward to do, see the
implementation for details:
7864607231/lua/null-ls/builtins/formatting/nix_flake_fmt.lua (L83-L110).
I recently discovered that my implementation was buggy (it didn't handle
flakes that expose a `formatter` package, such as nixpkgs), so I had to
rework the implementation:
https://github.com/nvimtools/none-ls.nvim/pull/272.
With the new `nix formatter build` command, I can delete all this akward
code, and it will be easier for other folks to build performant editor
integrations for `nix fmt`.
This refactor shouldn't change much except add a new `nix formatter run`
command. This creates space for the new `nix formatter build` command,
which I'll be introducing in the next commit.
Before the change `nix` was stripping warning flags
reported by `gcc-14` too eagerly:
$ nix build -f. texinfo4
error: builder for '/nix/store/i9948l91s3df44ip5jlpp6imbrcs646x-texinfo-4.13a.drv' failed with exit code 2;
last 25 log lines:
> 1495 | info_tag (mbi_iterator_t iter, int handle, size_t *plen)
> | ~~~~~~~~^~~~
> window.c:1887:39: error: passing argument 4 of 'printed_representation' from incompatible pointer type []
> 1887 | &replen);
> | ^~~~~~~
> | |
> | int *
After the change the compiler flag remains:
$ ~/patched.nix build -f. texinfo4
error: builder for '/nix/store/i9948l91s3df44ip5jlpp6imbrcs646x-texinfo-4.13a.drv' failed with exit code 2;
last 25 log lines:
> 1495 | info_tag (mbi_iterator_t iter, int handle, size_t *plen)
> | ~~~~~~~~^~~~
> window.c:1887:39: error: passing argument 4 of 'printed_representation' from incompatible pointer type [-Wincompatible-pointer-types]
> 1887 | &replen);
> | ^~~~~~~
> | |
> | int *
Note the difference in flag rendering around the warning.
https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda has a
good sumamry of why it happens. Befomre the change `nix` was handling
just one form or URL separator:
$ printf '\e]8;;http://example.com\e\\This is a link\e]8;;\e\\\n'
Now it also handled another for (used by gcc-14`):
printf '\e]8;;http://example.com\aThis is a link\e]8;;\a\n'
While at it fixed accumulation of trailing escape `\e\\` symbol.
sometimes it's these little things that let beginners stumble at the
first step...
mentioning one potentially foreign concept while introducing an entirely
new concept is asking enough already.
The explicit include is needed for clangd to not get confused somehow,
which is also what threw me off initially and made me pick the wrong
constructor.
The (pointer, number, number) constructor first constructs a C string
and then takes a substring from that, but we didn't specify that the
buffer needs to be NUL-terminated, and then what would be the point of
the size argument anyway...
basic_string.h:
> basic_string(const _Tp& __t, size_type __pos, size_type __n,
> const _Alloc& __a = _Alloc())
> : basic_string(_S_to_string_view(__t).substr(__pos, __n), __a) { }
Valgrind on nixops4/rust/nix-flake tests:
==1344422== Conditional jump or move depends on uninitialised value(s)
==1344422== at 0x48513E8: strlen (vg_replace_strmem.c:505)
==1344422== by 0x488E941: UnknownInlinedFun (char_traits.h:391)
==1344422== by 0x488E941: UnknownInlinedFun (string_view:141)
==1344422== by 0x488E941: UnknownInlinedFun (basic_string.h:790)
==1344422== by 0x488E941: nix_flake_reference_and_fragment_from_string (nix_api_flake.cc:81)
==1344422== by 0x127332: nix_flake::FlakeReference::parse_with_fragment (lib.rs:123)
It seems that the intention was to format a number in base 8 (as
suggested by the %o format specifier), but `perms` is a `std::string`
and not a number. Looks like `rawMode` is the correct thing to use here.
This name is close to the Nixpkgs lib function `escapeShellArg`,
making it easier to find.
A friendlier function with the same behavior as lib could be added
later.
Fixes
../src/libstore/unix/build/derivation-builder.cc:1130:86: warning: the compiler can assume that the address of ‘nix::DerivationBuilderParams::drv’ will never be NULL [-Waddress]
1130 | if (useChroot && settings.preBuildHook != "" && dynamic_cast<const Derivation *>(&drv)) {
| ^~~~
Assuming this check was left over from the time `drv` could be a
`BasicDerivation`.
I split it out before to try to separate the building logic, but now we
have the much better `DerivationBuilder` abstraction for that. With that
change, I think `LocalDerivationGoal` has outlived its usefulness.
We just inline it back into `DerivationGoal`, and do so with minimal
`#ifdef` for Windows.
Note that the order of statements in `~DerivationGoal` is different than
it was after the `~LocalDerivationGoal` split, but it is *restored* to
the way it original was before --- evidently I did the split slightly
wrong, but nobody noticed, probably because the order doesn't actually
matter.
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
... by moving our stuff out of the way from upstream's
`nixComponents` and `nixDependencies` attrsets.
(I prefer not to use overlays, but let's make it work this way
first)
Now that `DerivationBuilder` is created after the underlying data has
already been initialized, we can just refer this data normally, with a
direct reference.
Only `parsedDrv` takes a (borrowing) pointer, because independent of
initialization the derivation may or may not have structured attrs.
While it seems unlikely that `$USER` will be unset while `$HOME` is set,
as `$USER` is not used in the script and as `nix-profile-daemon.fish` is
not checking `$USER`, it seems better to remove this check.
`nix-profile.fish` and `nix-profile-daemon.fish` now become identical.
It seems reasonable to add both `$HOME/.profile/bin` and
`@localstatedir@/nix/profiles/default/bin` to `$PATH` for both user
local and daemon based nix execution. Nix daemon execution mode does
not affect these path.
The building logic is now free of the scheduling logic!
(The interface between them is just what is in the new header. This
makes it much easier to audit, and shrink over time.)
We have a new `DerivationBuilder` struct, and `DerivationBuilderParams`
`DerivationBuilderCallbacks` supporting it.
`LocalDerivationGoal` doesn't subclass any of these, so we are ready to
now move them out to a new file!
Now, most of it is in two new functions:
`LocalDerivationGoal::{,un}repareBuild`.
This might seems like a step backwards from coroutines --- now we have
more functions, and are stuck with class vars --- but I don't think it
needs to be.
There's a few options here:
- (Re)introduce coroutines for the isolated building logic. We could use the
same coroutines types, or simpler ones specialized to this use-case.
The `tryLocalBuild` caller can still use `Goal::Co`, and just will
manually "pump" this inner coroutine.
- Return closures from each step. This is sort of like coroutines by
hand, but it still allows us to stop writing down the local variables
in each type.
Being able to fully-use RAII again would be very nice!
- Keep top-level first-order functions like now, but make more
functional. Instead of having one state object (`DerivationBuilder`)
for all steps (setup, run, teardown), we can have separate structs for
the live variables at each point we consume and return.
This at least avoids "are these variables active at this time?"
questions, but doesn't give us the full benefit of RAII as we must
manually ensure FIFO create/destroy orders still.
One thing to note is that by keeping the `outputLock` unlocking in
`tryLocalBuild`, we are arguably uncovering a rebuild scheduling vs
building distinction, as the output locks are pretty squarely a
scheduling concern. It's nice that the builder doesn't need to know
about them at all.
We had fields set to the same values before in our test data. This is
not a problem per-se, but does mean we wouldn't catch certain mixups.
Now, the fields are set to distinct values (where possible), which makes
the test more robust.
This requires that we refer to the `sourceInfo` instead of the
`result`. However, `sourceInfo` does not create a chain of basedir
resolution, so we add that back with `flakeDir`.
Only a much smaller `StructuredAttrs` remains, the rest is is now moved
to `DerivationOptions`.
This gets us quite close to `std::optional<StructuredAttrs>` and
`DerivationOptions` being included in `Derivation` as fields.
Now, both the unit and functional tests relating to derivation options
are tested both ways -- with input addressing and content-addressing
derivations.
This is a small optimization used when we're signing a narinfo for
multiple keys in one go. Using this sign variant, we only compute the
NAR fingerprint once, then sign it with all the keys.
It is just use for adding context to errors, but we have `addTrace` to
do that. Let the callers do that instead.
The callers doing so is a bit duplicated, yes, but this will get better
once `DerivationOptions` is included in `Derivation`.
This fixes evaluation for Windows. There are unfortunately deps that
still don't build, but this can be fixed next.
Flake lock file updates:
• Updated input 'nixpkgs':
'github:NixOS/nixpkgs/52faf482a3889b7619003c0daec593a1912fddc1?narHash=sha256-6hl6L/tRnwubHcA4pfUUtk542wn2Om%2BD4UnDhlDW9BE%3D' (2025-03-30)
→ 'github:NixOS/nixpkgs/f675531bc7e6657c10a18b565cfebd8aa9e24c14?narHash=sha256-gbl9hE39nQRpZaLjhWKmEu5ejtQsgI5TWYrIVVJn30U%3D' (2025-04-09)
The STSProfileCredentialsProviders allows to assume a specific IAM role
when accessing an S3 repository. Sometimes this is needed to obtain the
permissions to operate on the bucket.
The "derivation" is one of the key concepts and captures the most distinctive aspect of Nix:
that we work with a certain type data (linked files) in a certain manner (using pure functions).
Here we finally arrange all the important pieces to show how they belong
together, while referring to the respective reference documentation for details.
This change also unbreaks downstream links to `//glossary#gloss-derivation`,
which had been broken by removing the glossary entry
Nix shipping with Yet Another Programming Language is often questioned
among beginners. This change highlights distinctive aspects of the Nix
language to ease the learning curve and better orient readers around
what really matters for using Nix.
Since it's on topic, this change also polishes the wording on the motivation for string contexts.
This change follows the definition from aptitude, but using precise notions from Nix:
> package managers deal with packages: collections of files that are
> bundled together and can be installed and removed as a group.
> [...]
> If a package A depends upon another package B, then B is required
> for A to operate properly.
> [...]
> The job of a package manager is to present an interface which assists
> the user in managing the collection of packages installed on his or her system.
>
> -- <https://www.debian.org/doc/manuals/aptitude/pr01s02.en.html>
An interesting addition:
> Packages are abstractions defining the granularity at which users can act
> (add, remove, upgrade, etc.) on available software.
> A distribution is a collection of packages maintained (hopefully) coherently.
>
> -- Package Upgrades in FOSS Distributions: Details and Challenges
> (Roberto Di Cosmo, Stefano Zacchiroli; 2009) <https://arxiv.org/pdf/0902.1610>
Notably these quotes and this change don't say anything about installation,
or what it means for software to be available. In practice, this is
handled downstream, e.g. in NixOS or Home Manager. Nix historically
provides rudimentary facilities for package management such as
`nix-env`, but I claim they are widely agreed upon being discouraged,
with plenty of arguments provided in <https://stop-using-nix-env.privatevoid.net>.
Similarly, the specific structure of packages is determined downstream,
since Nix is policy-free:
> Nix is policy-free; it provides mechanisms to implement various deployment policies, but does not enforce a specific one.
>
> -- The Purely Functional Software Deployment Model (Eelco Dolstra; 2006) <https://edolstra.github.io/pubs/phd-thesis.pdf>
Specifically, Nix mechanisms do not define what a package is supposed to be:
> It's worth noting that the Nix language is intended as a DSL for package and configuration management, but it has no notions of "packages" or "configurations".
>
> -- <https://gist.github.com/edolstra/29ce9d8ea399b703a7023073b0dbc00d>
This is why we say, Nix *allows* denoting packages in a certain way, but
doesn't enforce any particular way.
Rather than "mounting" the store inside an empty virtual filesystem,
just return the store as a virtual filesystem. This is more modular.
(FWIW, it also supports two long term hopes of mind:
1. More capability-based Nix language mode. I dream of a "super pure
eval" where you can only use relative path literals (See #8738), and
any `fetchTree`-fetched stuff + the store are all disjoint (none is
mounted in another) file systems.
2. Windows, where the store dir may include drive letters, etc., and is
thus unsuitable to be the prefix of any `CanonPath`s.
)
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
Add a `secretKeyFiles` URI parameter in the store URIs receiving a
coma-separated list of Nix signing keyfiles.
For instance:
nix copy --to "file:///tmp/store?secret-keys=/tmp/key1,/tmp/key2" \
"$(nix build --print-out-paths nixpkgs#hello)"
The keys passed through this new store URI parameter are merged with
the key specified in the `secretKeyFile` parameter, if any.
We'd like to rotate the signing key for cache.nixos.org. To simplify
the transition, we'd like to sign the new paths with two keys: the new
one and the current one. With this, the cache can support nix
configurations only trusting the new key and legacy configurations
only trusting the current key.
See https://github.com/NixOS/rfcs/pull/149 for more informations
behind the motivation.
nix> meson.build:216: WARNING: Project targets '>= 1.1' but uses feature introduced in '1.4.0': fs.name with build_tgt, custom_tgt, and custom_idx.
nix> meson.build:222: WARNING: Project targets '>= 1.1' but uses feature introduced in '1.4.0': fs.name with build_tgt, custom_tgt, and custom_idx.
nix> meson.build:235: WARNING: Project targets '>= 1.1' but uses feature introduced in '1.4.0': fs.name with build_tgt, custom_tgt, and custom_idx.
nix> meson.build:236: WARNING: Project targets '>= 1.1' but uses feature introduced in '1.4.0': fs.name with build_tgt, custom_tgt, and custom_idx.
nix> meson.build:242: WARNING: Project targets '>= 1.1' but uses feature introduced in '1.4.0': fs.name with build_tgt, custom_tgt, and custom_idx.
Revert most of "Hack together a fix for the public headers"
- The `libmain` change is kept, and one more libmain change is made.
(Need to update Meson and Nix per the package alike).
- The S3 situation is fixed in a different way: the variable is public
now, used in the header, and fixed accordingly.
- Fix TODO for `HAVE_EMBEDDED_SANDBOX_SHELL`
This reverts commit 2b51250534.
Previously, when lock file contained invalid JSON nix reported a parser
error without specifying the file it came from.
This change adds flake.lock file path to the error message to avoid
confusion.
Some of the maintainer attribute names got changed in nixos-unstable
(e.g. "edolstra" is now "eelco") but we want this flake to work on
nixos-24.11. So just get rid of them.
This is required for other bindings like nix-flake-c to hook into
nix-expr-c appropriately.
The `_internal` part should be a sufficient deterrent normally,
and it may also be useful for bindings that migrate from the C++
interface.
For people self-hosting caches that can be occasionally down, the
default timeout is very long. This is annoying if you are trying to
update your binary cache at the same time you are trying to update
another machine. Same if cachix has one of its rare hiccups.
We tested this value of 5s in srvos now for years and we like to travel
around the world with shitty internet, so it should be still reasonable
high.
For example, instead of doing
#include "nix/store-config.hh"
#include "nix/derived-path.hh"
Now do
#include "nix/store/config.hh"
#include "nix/store/derived-path.hh"
This was originally planned in the issue, and also recent requested by
Eelco.
Most of the change is purely mechanical. There is just one small
additional issue. See how, in the example above, we took this
opportunity to also turn `<comp>-config.hh` into `<comp>/config.hh`.
Well, there was already a `nix/util/config.{cc,hh}`. Even though there
is not a public configuration header for libutil (which also would be
called `nix/util/config.{cc,hh}`) that's still confusing, To avoid any
such confusion, we renamed that to `nix/util/configuration.{cc,hh}`.
Finally, note that the libflake headers already did this, so we didn't
need to do anything to them. We wouldn't want to mistakenly get
`nix/flake/flake/flake.hh`!
Progress on #7876
Previously, when users entered an incomplete expression in the REPL,
the continuation prompt was just 10 blank spaces, which looked invisible
and gave the impression that the REPL had stalled.
This change updates the prompt to " > ", aligning it visually
with 'nix-repl> ' and clearly indicating that the REPL is waiting for
more input.
Fixes: https://github.com/NixOS/nix/issues/12702
There are two big changes:
1. Public and private config is now separated. Configuration variables
that are only used internally do not go in a header which is
installed.
(Additionally, libutil has a unix-specific private config header,
which should only be used in unix-specific code. This keeps things a
bit more organized, in a purely private implementation-internal way.)
2. Secondly, there is no more `-include`. There are very few config
items that need to be publically exposed, so now it is feasible to
just make the headers that need them just including the (public)
configuration header.
And there are also a few more small cleanups on top of those:
- The configuration files have better names.
- The few CPP variables that remain exposed in the public headers are
now also renamed to always start with `NIX_`. This ensures they should
not conflict with variables defined elsewhere.
- We now always use `#if` and not `#ifdef`/`#ifndef` for our
configuration variables, which helps avoid bugs by requiring that
variables must be defined in all cases.
See comments on the script; this is supposed to avoid breaking muscle
memory without complicating the build system (which proved harder than I
thought too) or not doing the header hygiene change at all.
link-headers: use pathlib consistenly and fix type errors
The short answer for why we need to do this is so we can consistently do
`#include "nix/..."`. Without this change, there are ways to still make
that work, but they are hacky, and they have downsides such as making it
harder to make sure headers from the wrong Nix library (e..g.
`libnixexpr` headers in `libnixutil`) aren't being used.
The C API alraedy used `nix_api_*`, so its headers are *not* put in
subdirectories accordingly.
Progress on #7876
We resisted doing this for a while because it would be annoying to not
have the header source file pairs close by / easy to change file
path/name from one to the other. But I am ameliorating that with
symlinks in the next commit.
- Since it's now private, give it a rename. Note that I want to switch the
word order on the public ones too.
- Since it is only needed by two files, just include there rather than
the nasty blanket-forced thing.
On my system (Ubuntu 24.04 with nix installed using
https://zero-to-nix.com/), I noticed that my PATH
contained multiple times the following entries:
/home/thomas/.nix-profile/bin
/nix/var/nix/profiles/default/bin
Fix it by inserting a missing `export`, to make
sure `nix-daemon.sh` is really only executed once.
This makes it behave the same as nix-daemon. Opening the store in the
parent can cause a SIGBUS in libsqlite in the child:
#0 0x00007f141cf6f789 in __memset_avx2_unaligned_erms () from /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libc.so.6
#1 0x00007f141c322fe8 in walIndexAppend () from /nix/store/bbd59cqw259149r2ddk4w1q0lr2fch8c-sqlite-3.46.1/lib/libsqlite3.so.0
#2 0x00007f141c3711a2 in pagerWalFrames () from /nix/store/bbd59cqw259149r2ddk4w1q0lr2fch8c-sqlite-3.46.1/lib/libsqlite3.so.0
#3 0x00007f141c38317e in sqlite3PagerCommitPhaseOne.part.0 () from /nix/store/bbd59cqw259149r2ddk4w1q0lr2fch8c-sqlite-3.46.1/lib/libsqlite3.so.0
#4 0x00007f141c383555 in sqlite3BtreeCommitPhaseOne.part.0 () from /nix/store/bbd59cqw259149r2ddk4w1q0lr2fch8c-sqlite-3.46.1/lib/libsqlite3.so.0
#5 0x00007f141c384797 in sqlite3VdbeHalt () from /nix/store/bbd59cqw259149r2ddk4w1q0lr2fch8c-sqlite-3.46.1/lib/libsqlite3.so.0
#6 0x00007f141c3b8f60 in sqlite3VdbeExec () from /nix/store/bbd59cqw259149r2ddk4w1q0lr2fch8c-sqlite-3.46.1/lib/libsqlite3.so.0
#7 0x00007f141c3bbfef in sqlite3_step () from /nix/store/bbd59cqw259149r2ddk4w1q0lr2fch8c-sqlite-3.46.1/lib/libsqlite3.so.0
#8 0x00007f141c3bd0e5 in sqlite3_exec () from /nix/store/bbd59cqw259149r2ddk4w1q0lr2fch8c-sqlite-3.46.1/lib/libsqlite3.so.0
#9 0x00007f141da140e0 in nix::SQLiteTxn::commit() () from /nix/store/1m4r8s7s1v54zq9isncvjgia02bffxlz-determinate-nix-store-3.1.0/lib/libnixstore.so
#10 0x00007f141d9ce69c in nix::LocalStore::registerValidPaths(std::map<nix::StorePath, nix::ValidPathInfo, std::less<nix::StorePath>, std::allocator<std::pair<nix::StorePath const, nix::ValidPathInfo> > > const&)::{lambda()#1}::operator()() const () from /nix/store/1m4r8s7s1v54zq9isncvjgia02bffxlz-determinate-nix-store-3.1.0/lib/libnixstore.so
- Some headers were completely redundant and have been removed.
- Other headers have been turned private.
- Unnecessary meson.build code has been removed.
- libutil-tests now has a private config header, where previously
it had none. This removes the need to expose a package version
macro publicly.
We rely on `yyerror()` instead.
> The variable yynerrs contains the number of syntax errors reported so
> far.
> Normally this variable is global; but if you request a pure parser
> (see A Pure (Reentrant) Parser) then it is a local variable which only
> the actions can access.
https://www.gnu.org/software/bison/manual/html_node/Error-Reporting-Function.html
at least clang-tidy is not convinced that this initialized.
If this is not the case, the impact should be small and hopefully also
more robust if changed.
Otherwise without the change the test fails on nix-2.26 as:
error: derivation contains an illegal reference specifier 'dev'
Note: the error message does not match intended change.
Before the change "illegal reference" was hard to interpret as it did
not mention what derivation actually hits it.
Today's `nixpkgs` example:
Before the change:
$ nix build --no-link -f. postgresql_14
...
error: derivation contains an illegal reference specifier 'man'
After the change:
$ nix build --no-link -f. postgresql_14
...
error: derivation '/nix/store/bxp6g57limvwiga61vdlyvhy7i8rp6wd-postgresql-14.15.drv' output check for 'lib' contains an illegal reference specifier 'man', expected store path or output name (one of [debug, dev, doc, lib, out])
After the previous commit it should not be necessary. Furthermore, if we
*do* sleep, we'll exacerbate a race condition (in conjunction with
getting rid of the thread cancellation) that will cause test failures.
This was filed as https://github.com/nixos/nix/issues/7584, but as far
as I can tell, the previous solution of POLLHUP works just fine on macOS
14. I've also tested on an ancient machine with macOS 10.15.7, which
also has POLLHUP work correctly.
It's possible this might regress some older versions of macOS that have
a kernel bug, but I went looking through the history on the sources and
didn't find anything that looked terribly convincingly like a bug fix
between 2020 and today. If such a broken version exists, it seems pretty
reasonable to suggest simply updating the OS.
Change-Id: I178a038baa000f927ea2cbc4587d69d8ab786843
Based off of commit 69e2ee5b25752ba5fd8644cef56fb9d627ca4a64. Ericson2314 added
additional other information.
On https://github.com/NixOS/nix/issues/8946, we faced a surprising
behaviour wrt. exception when using pthread_cancel. In a nutshell when
a thread is inside a catch block and it's getting pthread_cancel by
another one, then the original exception is bubbled up and crashes the
process.
We now poll on the notification pipe from the thread and exit when the
main thread closes its end. This solution does not exhibit surprising
behaviour wrt. exceptions.
Co-authored-by: Mic92 <joerg@thalheim.io>
Fixes https://github.com/NixOS/nix/issues/8946
See also Lix https://gerrit.lix.systems/c/lix/+/1605 which is very
similar by coincidence. Pulled a comment from that.
Without this :u, :sh and :i repl commands fail with:
> Cannot run 'nix-shell'/`nix-env` because no method of calling the Nix
> CLI was provided. This is a configuration problem pertaining to how
> this program was built.
Remove the default ctor argument as it evidently makes catching
refactoring bugs much harder. `NixRepl` implementation lives completely
in `repl.cc`, so we can be as explicit as necessary.
We want the $doc, $man outputs to be symlinks pointing to nix-manual and
nix-manual.man. Creating the directories first makes the `ln` command
produce symlink $doc/${nix-manual} instead.
```
$file /nix/store/q4dwlnd36gpfajgfcp6hca2xwy068wjq-nix-2.27.1-man/rwh8ky3k040wyrywl8k2v5b3csdfbdg7-nix-manual-2.27.1-man
/nix/store/q4dwlnd36gpfajgfcp6hca2xwy068wjq-nix-2.27.1-man/rwh8ky3k040wyrywl8k2v5b3csdfbdg7-nix-manual-2.27.1-man:
symbolic link to /nix/store/rwh8ky3k040wyrywl8k2v5b3csdfbdg7-nix-manual-2.27.1-man
```
This is the reason `nix-env --help` is once again broken on 2.26/2.27/master
after 4108529.
Instead of calling `worker.waitForAWhile(shared_from_this())` etc.,
the subclasses of Goal instead call protected functions defined in Goal
that abstract over these.
The code for awaiting has also been heavily simplified.
Instead of calling `addWaitee`, then suspending,
`co_await await(waitees)` is called once, which also handles the suspend.
The end-goal is to remove all manual `co_await Suspend{}`s.
We now see exception beeing thrown when remote building in master
because of writing to a non-blocking file descriptor from our json logger.
> #0 0x00007f2ea97aea9c in __pthread_kill_implementation () from /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libc.so.6
> #1 0x00007f2ea975c576 in raise () from /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libc.so.6
> #2 0x00007f2ea9744935 in abort () from /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libc.so.6
> #3 0x00007f2ea99e8c2b in __gnu_cxx::__verbose_terminate_handler() [clone .cold] () from /nix/store/ybjcla5bhj8g1y84998pn4a2drfxybkv-gcc-13.3.0-lib/lib/libstdc++.so.6
> #4 0x00007f2ea99f820a in __cxxabiv1::__terminate(void (*)()) () from /nix/store/ybjcla5bhj8g1y84998pn4a2drfxybkv-gcc-13.3.0-lib/lib/libstdc++.so.6
> #5 0x00007f2ea99f8275 in std::terminate() () from /nix/store/ybjcla5bhj8g1y84998pn4a2drfxybkv-gcc-13.3.0-lib/lib/libstdc++.so.6
> #6 0x00007f2ea99f84c7 in __cxa_throw () from /nix/store/ybjcla5bhj8g1y84998pn4a2drfxybkv-gcc-13.3.0-lib/lib/libstdc++.so.6
> #7 0x00007f2eaa5035c2 in nix::writeFull (fd=2, s=..., allowInterrupts=true) at ../unix/file-descriptor.cc:43
> #8 0x00007f2eaa5633c4 in nix::JSONLogger::write (this=this@entry=0x249a7d40, json=...) at /nix/store/4krab2h0hd4wvxxmscxrw21pl77j4i7j-gcc-13.3.0/include/c++/13.3.0/bits/char_traits.h:358
> #9 0x00007f2eaa5658d7 in nix::JSONLogger::logEI (this=<optimized out>, ei=...) at ../logging.cc:242
> #10 0x00007f2ea9c5d048 in nix::Logger::logEI (ei=..., lvl=nix::lvlError, this=0x249a7d40) at /nix/store/a7cq5bqh0ryvnkv4m19ffchnvi8l9qx6-nix-util-2.27.0-dev/include/nix/logging.hh:108
> #11 nix::handleExceptions (programName="nix", fun=...) at ../shared.cc:343
> #12 0x0000000000465b1f in main (argc=<optimized out>, argv=<optimized out>) at /nix/store/4krab2h0hd4wvxxmscxrw21pl77j4i7j-gcc-13.3.0/include/c++/13.3.0/bits/allocator.h:163
> (gdb) frame 10
> #10 0x00007f2ea9c5d048 in nix::Logger::logEI (ei=..., lvl=nix::lvlError, this=0x249a7d40) at /nix/store/a7cq5bqh0ryvnkv4m19ffchnvi8l9qx6-nix-util-2.27.0-dev/include/nix/logging.hh:108
> 108 logEI(ei);
So far only drainFD sets the non-blocking flag on a "readable" file descriptor,
while this is a "writeable" file descriptor.
It's not clear to me yet, why we see logs after that point, but it's
also not that bad to handle EAGAIN in read/write functions after all.
Now that we have coroutines, we can go back to loops and regular RAII,
which is must less error-proone!
I look forward to removing the other instances!
Perhaps more significantly, it no longer knows about
`LocalDerivationGoal`, and without any effort it also compiles on
Windows just fine. (`local-derivation-goal.{cc,hh}` is currently skipped
on Windows.)
Default: istty(stdout)
This refactors `nix develop` internals a bit to use the `json` type
more. The assertion now operates in the in-memory json instead of
re-parsing it. While this is technically a weaker guarantee, we
should be able to rely on the library to get this right. It's its
most essential purpose.
The underlying issue is that debugger code path was
calling PosTable::operator[] in each eval method.
This has become incredibly expensive since 5d9fdab3de.
While we are it it, I've reworked the code to
not use std::shared_ptr where it really isn't necessary.
As I've documented in previous commits, this is actually
more a workaround for recursive header dependencies now
and is only necessary in `error.hh` code.
Some ad-hoc benchmarking:
After this commit:
```
Benchmark 1: nix eval nixpkgs#hello --impure --ignore-try --no-eval-cache --debugger
Time (mean ± σ): 784.2 ms ± 7.1 ms [User: 561.4 ms, System: 147.7 ms]
Range (min … max): 773.5 ms … 792.6 ms 10 runs
```
On master 3604c7c51:
```
Benchmark 1: nix eval nixpkgs#hello --impure --ignore-try --no-eval-cache --debugger
Time (mean ± σ): 22.914 s ± 0.178 s [User: 18.524 s, System: 4.151 s]
Range (min … max): 22.738 s … 23.290 s 10 runs
```
All of this code doesn't actually depend on anything from
libexpr. Because Pos is so tigtly coupled with Error, it
makes sense to have in the same library.
The simplification here is due to a long-standing bug, but it is not
worth fixing the bug at this time. Instead we've finally written up an
issue for the bug, and referenced the issue number in the code.
In the local building case, there is many things which can through
`BuildError`, but in the hook case there is just this one. We can
therefore simplify the code by "cinching" down the logic just to the
spot the error is thrown.
There is other code outside `libstore/build` which also uses
`BuildError`, but I believe those cases are mistakes. The point of
`BuildError` is the narrow technical use-cases of "errors which should
not be fatal with `--keep-going`". Using it outside the
building/scheduling code doesn't really make sense in that regard. It
seems likely that those usages were instead merely because "oh, this
error has something to do with building, so I guess `BuildError` is
better than `Error`".
It is quite likely that I myself used `BuildError` incorrectly as
described above :).
The variables are only set by CGroup mechanisms in `killSandbox` in the
local build. In the build hook case, these variables will not be set, so
there is nothing to do.
We can move this method from `LocalStore` to `Store` --- even if we only
want the actual builder to sign things in many cases, there is no reason
to try to enforce this policy by spurious moving the method to a
subclass.
Now, we might technically sign class, but CA derivations is
experimental, and @Ericson2314 is going to revisit all this stuff with
issue #11896 anyways.
- `chrootParentDir` can be a local variable instead of a class variable.
- `getChildStatus` can be inlined. Again, we have the `assert(!hook);`
in the local building case, which makes for a simpler thing inlined.
Thanks to the previous commit, we can inline all these small callbacks.
In the build-hook case, they were empty, and now they disappear
entirely.
While `LocalDerivationGoal` can be used in the hook case (we use it
based on whether we have a local store, not based on whether we are
using the build hook, a decision which comes later), the previous
commit's inline moved the code into a spot where we know we are cleaning
up after local building, *not* after running the build hook. This allows
for much more simplification.
The basic idea is that while we have duplicated this function, we now
have one call-site in the local build case, and one call site in the
build hook case. This unlocks big opportunities to specialize each copy,
since they really shouldn't be doing the same things. By the time we are
are done, there should not be much duplication left.
See #12628 for further info.
This is supposed to firstly improve the docs as they are, and secondly
hint at how the core conceptual information ought to be moved to the
store derivation section of the manual.
Co-authored-by: Jörg Thalheim <Mic92@users.noreply.github.com>
This variable was once used to communicate already acquired store path
locks between Nix and the build hook, but this hasn't been the case
since 9bcb4d2dd9. So let's get rid of
it.
It was first introduced in 19e0ce2c03
In Nix we only register the crash handler in main instead of initNix,
because library user may want to use their own crash handler.
Sample output:
Mar 12 08:38:06 eve nix[2303762]: Nix crashed. This is a bug. Please report this at https://github.com/NixOS/nix/issues with the following information included:
Mar 12 08:38:06 eve nix[2303762]: Exception: nix::SysError: error: writing to file: Resource temporarily unavailable
Mar 12 08:38:06 eve nix[2303762]: Stack trace:
Mar 12 08:38:06 eve nix[2303762]: 0# 0x000000000076876A in nix
1# 0x00007FDA40E9F20A in /nix/store/2lhklm5aizx30qbw49acnrrzkj9lbmij-gcc-14-20241116-lib/lib/libstdc++.so.6
2# std::unexpected() in /nix/store/2lhklm5aizx30qbw49acnrrzkj9lbmij-gcc-14-20241116-lib/lib/libstdc++.so.6
3# 0x00007FDA40E9F487 in /nix/store/2lhklm5aizx30qbw49acnrrzkj9lbmij-gcc-14-20241116-lib/lib/libstdc++.so.6
4# nix::writeFull(int, std::basic_string_view<char, std::char_traits<char> >, bool) in /home/joerg/git/nix/inst/lib/libnixutil.so
5# nix::writeLine(int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) in /home/joerg/git/nix/inst/lib/libnixutil.so
6# nix::JSONLogger::write(nlohmann::json_abi_v3_11_3::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::json_abi_v3_11_3::adl_serializer, std::vector<unsigned char, std::allocator<unsigned char> >, void> const&) in /home/joerg/git/nix/inst/lib/libnixutil.so
7# nix::JSONLogger::logEI(nix::ErrorInfo const&) in /home/joerg/git/nix/inst/lib/libnixutil.so
8# nix::Logger::logEI(nix::Verbosity, nix::ErrorInfo) in nix
9# nix::handleExceptions(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::function<void ()>) in /home/joerg/git/nix/inst/lib/libnixmain.so
10# 0x000000000087A563 in nix
11# 0x00007FDA40BD41FE in /nix/store/6q2mknq81cyscjmkv72fpcsvan56qhmg-glibc-2.40-66/lib/libc.so.6
12# __libc_start_main in /nix/store/6q2mknq81cyscjmkv72fpcsvan56qhmg-glibc-2.40-66/lib/libc.so.6
13# 0x00000000006F4DF5 in nix
Co-authored-by: eldritch horrors <pennae@lix.systems>
1. Fix confusing wording that might imply unnecessary double-hashing.
2. Add references to specifics of base-32 encoding.
3. Fix incorrect description that sha256 hash of `fingerprint` is
truncated. "Truncated" is actual wording used in Nix theses, but it has
unusual meaning, that is better conveyed by word "compressed", which is
used by the reference C++ implementation.
4. Clarify details of base16 encoding.
Doing this makes catching non-obvious bugs easier. GHA CI workload is
already a concern and there isn't much benefit in running the tests with
and without sanitizers at the same time, so UBSAN is enabled for default
checks.
This change doesn't affect production builds in any way, but is rather a
step in the direction of improving automated testing during development.
Relates to #10969.
This fixes a few of the property tests, now that the property tests
are actually generating arbitrary data - some of that data now
requiring experimental features to function properly.
Here we're switching to combinators instead of dereference operator.
It turns out the dereference operator was being executed upon test
setup, meaning that we were only using a only single value for each of
the executions of the property tests! Really not good.
And on Windows, we instead get:
operator* is not allowed in this context
ff6af6fc68/src/gen/detail/GenerationHandler.cpp (L16C31-L16C71)
Now a few of the property tests fail, because we're generating cases
which haven't been exercised before.
I refactored the way that input resolution works in `DerivationGoal`. To
be honest, it is probably unclear to the reader whether this new way is
better or worse. I suppose *intrinsic* motivation, I can say that
- the more structured use of `inputGoal` (a local variable) is better
than the shotgrun approach with `inputDrvOutputs`
- A virtual `waiteeDone` was a hack, and now it's gone.
However, the *real* motivation of this is not the above things, but that
it is needed for my mammoth refactor fixing #11897 and #11928.
It is nice that this step could come first, rather than making that
refactor even bigger.
The bug reappeared after all, and the fix introduced a different bug. I
just reverted on 2.27 first, in #12576, but upon further introspection
and discussion with @roberth, with preparing for and travelling to
Planet Nix I will not be able to fix it on `master` soon enough for a
revert to not be warranted here in the meantime also.
This reverts commit c98525235f.
This should fix a few packaging regressions.
`dev` also includes a merged `includes/`, which may be helpful until
inter-component includes are fixed properly.
It's not very clear what the ownership model is here, but one thing
is certain: `.up` can't be destroyed before the StaticEnv that refers
to it is.
Changing a non-owning pointer to taking shared ownership of the parent
`StaticEnv` prevents the `.up` from being freed.
I'm not a huge fan of the inverted ownership, where child `StaticEnv`
takes a refcount of the parent, but this seems like the least intrusive
way to fix the use-after-free.
This shouldn't cause any shared_ptr cycles to appear (hopefully).
When #9863 converted the `Nix::Store` free functions into member functions, the
implicit `this` argument was not accounted for when iterating over the variable
number of arguments in some functions.
Seems like this got dropped at some point during meson migration, so
put it back in the build system.
Drop all tests for `parseGitUrl`, since that function doesn't exist
and migrating doesn't look sensible because git-lfs stuff seems to use
`ParsedURL`.
Note that in pure mode, we don't need to use the union FS even when
using a chroot store, since the user shouldn't have access to the
physical /nix/store.
This makes `nix.version` quicker to evaluate, which should speed up
package listing operations.
If you want an accurate count, use `lib.optionals` in your override
instead of `null` values.
By appending a colon to MANPATH NIX_MAN_DIR gets prepended to the
final MANPATH before default search paths.
This makes man still consider default search paths, but prefers
NIX_MAN_DIR (if it exists).
It still makes sense to point NIX_MAN_DIR to a correct location
by moving man pages build from nix-manual.man to nix-cli.man, but
this should fix most common use-cases where nix is installed globally.
... as intended.
Requirements:
- don't build fresh libraries for each git commit
- have git commit in the CLI
Bug:
- echo ${version} went into the wrong file => use the fact that it's
a symlink, not just for reading but also for writing.
Logging to another Logger was kind of nonsensical - it was really just
an easy way to get it to write its output to stderr, but that only
works if the underlying logger writes to stderr.
This change is needed to make it easy to log JSON output somewhere
else (like a file or socket).
It is unused in Nix currently, but will be used in Hydra. This reflects
what Hydra does in https://github.com/NixOS/hydra/pull/1387.
We may probably to use it more widely for better SSH store performance,
but this needs to be subject to more testing before we do that.
This is a first step towards PR #10760, and the issues it addresses.
See the Doxygen for details.
Thanks to these changes, we are able to drastically restrict how the
rest of the code-base uses `ParseDerivation`.
Co-Authored-By: HaeNoe <git@haenoe.party>
It's best we teach users that the "foo" derivation is less than pure in the sense that it cannot be built just on any system, in particular that builders cannot be selected arbitrarily but based on their system-features. The `"recursive-nix"` system-feature is automatically defined by `--extra-experimental-features recursive-nix`
I do not believe there is any problem with computing
`hashDerivationModulo` the normal way with impure derivations.
Conversely, the way this used to work is very suspicious because two
almost-equal derivations that only differ in depending on different
impure derivations could have the same drv hash modulo. That is very
suspicious because there is no reason to think those two different
impure derivations will end up producing the same content-addressed
data!
Co-authored-by: Alain Zscheile <zseri.devel@ytrizja.de>
E.g. in a derivation attribute `foo = ./bar`, if ./bar is a symlink,
we should copy the symlink to the store, not its target. This restores
the behaviour of Nix <= 2.19.
"content-address*ed*" derivation is misleading because all derivations
are *themselves* content-addressed. What may or may not be
content-addressed is not derivation itself, but the *output* of the
derivation.
The outputs are not *part* of the derivation (for then the derivation
wouldn't be complete before we built it) but rather separate entities
produced by the derivation.
"content-adddress*ed*" is not correctly because it can only describe
what the derivation *is*, and that is not what we are trying to do.
"content-address*ing*" is correct because it describes what the
derivation *does* --- it produces content-addressed data.
This is a big step documenting the store layer on its own, separately from the evaluator (and `builtins.derivation`).
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Curl creates sockets without setting FD_CLOEXEC/SOCK_CLOEXEC, this can
cause connections to remain open forever when using commands like `nix
shell`
This change sets the FD_CLOEXEC flag using a CURLOPT_SOCKOPTFUNCTION
callback.
This seems to be the way to do it now, even though I can't run them
without setting at least one env var.
I'll only fix shellcheck for now. Don't shoot the messenger.
It isn't quite clear to me why the previous commit masked this problem,
but I'm glad shellcheck has an effect or more effect now.
Note that this is just a script that is meant to run outside a
derivation (but also can be called by a derivation builder).
`touch $out` does not belong in it.
`touch $out` worked accidentally in the derivation-based check,
and also in the dev shell, but if pre-commit is invoked without
the dev shell it would fail.
This uses the single-threaded C-based routines from libblake3.
This is not optimal performance-wise but should be a good starting point
for nix compatibility with BLAKE3 hashing until a more performant
implementation based on the multi-threaded BLAKE3 routines
(written in Rust) can be developed.
This fixes dynamic derivations, reverting #9081.
I believe that this time around, #9052 is fixed. When I first rebased
this, tests were failing (which wasn't the case before). The cause of
those test failures were due to the crude job in which the outer goal
tried to exit with the inner goal's status.
Now, that error handling has been reworked to be more faithful. The exit
exit status and exception of the inner goal is returned by the outer
goal. The exception was what was causing the test failures, but I
believe it was not having the right error code (there is more than one
for failure) that caused #9081.
The only cost of doing things the "right way" was that I had to
introduce a hacky `preserveException` boolean. I don't like this, but,
then again, none of us like anything about how the scheduler works.
Issue #11927 is still there to clean everything up, subsuming the need
for any `preserveException` because I doubt we will be fishing
information out of state machines like this at all.
This reverts commit 8440afbed7.
Co-Authored-By: Eelco Dolstra <edolstra@gmail.com>
There seems to be no good reason for `nix-profile.fish` and
`nix-profile-daemon.fish` to differ in how they look for the location of
the `ca-bundle.crt` that might be installed by one of the packages.
As `$NIX_PROFILES` points to user local paths, not checking there is
strictly less useful, it seems?
Using `set --local` is better than using `set`/`set --erase`. `--local`
will preserve any existing `NIX_LINK` value. And the local variable is
automatically removed for any execution path.
This allows a flake to specify that it needs Git submodules to be
enabled (or disabled, if we ever change the default) on the top-level
flake. This requires the input to be refetched, but since the first
fetch is lazy, this shouldn't be expensive.
Currently the only attribute allowed by `inputs.self` is `submodules`,
but more can be added in the future (e.g. a `lazy` attribute to opt in
to lazy tree behaviour).
Fixes#5312, #9842.
It seems reasonable to add the `share` folder from the user profile into
`$XDG_DATA_DIRS` both for daemon and profile execution. Nix could add
package shared files into this folder regardless of how the nix daemon
itself is running.
If we previously fetched by revision, the output of "git ls-remote"
won't start with the expected line like
ref: refs/heads/master HEAD
but will be something like
5c4410e3b9891c05ab40d723de78c6f0be45ad30 refs/heads/5c4410e3b9891c05ab40d723de78c6f0be45ad30
This then causes Nix to treat that revision as a refname, which then
leads to warnings like
warning: could not update cached head '5c4410e3b9891c05ab40d723de78c6f0be45ad30' for 'file:///tmp/repo'
This causes Git to create a local ref named refs/head/<rev>, e.g.
$ git -C ~/.cache/nix/gitv3/11irpim06vj4h6c0w8yls6kx4hvl0qd0gr1fvk47n76g6wf1s1vk ls-remote --symref .
5c4410e3b9891c05ab40d723de78c6f0be45ad30 refs/heads/5c4410e3b9891c05ab40d723de78c6f0be45ad30
7f6bde8a20de4cccc2256f088bc5af9dbe38881d refs/heads/7f6bde8a20de4cccc2256f088bc5af9dbe38881d
which confuses readHead(), leading to errors like
fatal: Refusing to point HEAD outside of refs/
warning: could not update cached head 'd275d93aa0bb8a004939b2f1e87f559f989453be' for 'file:///tmp/repo'
Git interprets them as part of the file name, so passing parameters
like 'rev' breaks. Only relevant for testing (when _NIX_FORCE_HTTP is
set) and local bare repos.
Fixes messages like 'copying /tmp/repo/tmp/repo to the store'. The
PosixSourceAccessor already sets the prefix. Setting the prefix twice
shouldn't be a problem, but GitRepoImpl::getAccessor() returns a
wrapped accessor so it's not actually idempotent.
It seems that `meson test --print-errorlogs` only captures stderr,
so this makes it forward the logs as intended.
We might want to redirect stdout in our common setup script instead.
The main improvement is that the new message gives an example of a path
that is referenced, which should make it easier to track down. While
there, I also clarified the wording, saying exactly why the paths in
question were illegal.
Not sure what the intent was expecting help.sh to fail in the main suite, but it caused `meson test` to fail inside a `nix develop` shell:
$ meson test help --print-errorlogs
ninja: Entering directory `/home/eelco/Dev/nix-master/build'
1/1 nix-functional-tests:main / help UNEXPECTEDPASS 4.02s
I started getting these warnings `warning: download buffer is full; consider increasing the 'download-buffer-size' setting` but the documentation does not make it obvious what unit of measurement it accepts.
1. Fix this eval error:
https://hydra.nixos.org/jobset/nix/master#tabs-errors
The dev package output (actually a separate derivation) needs to skip
this for cross just as the main package output does.
2. Deduplicate libs attrset and list.
3. Move `nix-functional-tests` to `checkInputs`.
With the Meson build system, we no longer need a `check` vs
`install-check` distinction, so it is simpler to just keeep
everything in one place.
This label will be useful for constructing queries to find backportable PRs.
Specifically, those should omit both automatic backports and
"backports reviewed" PRs.
This allows RemoteStore::addMultipleToStore() to free the Source
objects early (and in particular the associated sinkToSource()
buffers). This should fix#7359. For example, memory consumption of
nix copy --derivation --to ssh-ng://localhost?remote-store=/tmp/nix --derivation --no-check-sigs \
/nix/store/4p9xmfgnvclqpii8pxqcwcvl9bxqy2xf-nixos-system-...drv
went from 353 MB to 74 MB.
Fixes
$ nix copy --derivation --to /tmp/nix /nix/store/...
error: cannot enqueue a work item while the thread pool is shutting down
The ThreadPoolShutDown exception was hiding the reason for the thread
pool shut down, e.g.
error: cannot add path '/nix/store/03sl46khd8gmjpsad7223m32ma965vy9-fix-static.patch' because it lacks a signature by a trusted key
In order for the script not be sourced multiple times by the same shell
instance, `__ETC_PROFILE_NIX_SOURCED` needs to be set with a `--global`
flag.
Both files are almost identical. And style differences make it harder
to see what is actually different and keep them in sync, when it is
required.
`nix-profile.fish` and part of `nix-profile-daemon.fish` use 4 space
indentation. Which is also the indentation that the fish shell
documentation is using.
Reformatting a chunk of `nix-profile-daemon.fish` from 2 space
indentation to 4 space indentation for consistency.
- Multiple choices of stdenv are handled more consistently, especially for the dev
shells which were previously not done correctly.
- Some stray nix code was moving into the `packaging` directory
nix-env can read priorities from a derivations meta attributes, but this
only works when installing a nix expression.
nix-env can also install bare store paths, however meta attributes are
not readable in that case. This means that a store path can not be
installed with a specific priority.
Some cases where it is advantageous to install a store path: a remote
host following a `nix copy`, or any time you want to save some
evaluation time and happen to already know the store path.
This PR addresses this shortcoming by adding a --priority flag to
nix-env --install.
Since ff8e2fe84e, 'path:' URLs on the
CLI are interpreted as relative to the current directory of the user,
not the path of the flake we're overriding.
During garbage collection we cache several things -- a set of known-dead
paths, a set of known-alive paths, and a map of paths to their derivers.
Currently they use STL maps and sets, which are ordered structures that
typically are backed by binary trees. Since we are putting pseudorandom
paths into these and looking them up by exact key, we don't need the
ordering, and we're paying a nontrivial cost per insertion.
The existing maps require O(n log n) memory and have O(log n) insertion
and lookup time.
We could instead use unordered maps, which are typically backed by
hashmaps. These require O(n) memory and have O(1) insertion and lookup
time.
On my system this appears to result in a dramatic speedup -- prior to
this patch I was able to delete 400k paths out of 9.5 million over the
course of 34.5 hours. After this patch the same result took 89 minutes.
This result should NOT be taken at face value because the two runs
aren't really comparable; in particular the first started when I had 9.5
million store paths and the seconcd started with 7.8 million, so we are
deleting a different set of paths starting from a much cleaner
filesystem. But I do think it's indicative.
Related: https://github.com/NixOS/nix/issues/9581
This fixes segfaults with nix copy when there was an error processing
addMultipleToStore.
Running with ASAN/TSAN pointed at an use-after-free with threads from
the pool accessing the graph declared in processGraph after the function
was exiting and destructing the variables.
It turns out that if there is an error before pool.process() is called,
for example while we are still enqueuing tasks, then pool.process()
isn't called and threads are still left to run.
By creating the pool last we ensure that it is stopped first before
running other destructors even if an exception happens early.
[ lix porting note: nix does not name threads so the patch has been
adapted to not pass thread name ]
Link: https://git.lix.systems/lix-project/lix/issues/618
Link: https://gerrit.lix.systems/c/lix/+/2355
This allows writing lock files with dirty inputs, so long as they have
a NAR hash. (Currently they always have a NAR hash, but with lazy
trees that may not always be the case.)
Generally dirty locks are bad for reproducibility (we can detect if
the dirty input has changed, but we have no way to fetch it except
substitution). Hence we don't allow them by default.
Fixes#11181.
Commands like `nix flake metadata '.?submodules=1'` ignored the query
part of the URL, while `nix build '.?submodules=1#foo'` did work
correctly because of the presence of the fragment part.
The current instructions for building the Nix manual include a command that doesn't work as described. Specifically:
```
nix build .#nix^doc
```
Running this command results in the error:
```
error: derivation '/nix/store/hddqxzfqgx2fhj8q66ss3idym7pk7aj1-nix-2.26.0pre20250107_383ab87.drv' does not have wanted outputs 'doc'
```
However, this command works if you specify the Nix version explicitly, such as:
```
nix build nix/2.24.11#nix^doc
```
Additionally, these commands are run within the Nix root directory.
However, the nix build .#nix^doc command does work when run from the nixpkgs directory and generates the NixOS manual.
I'm not sure if I'm missing something. Is the `nix^doc` supposed to be added somehow to flake outputs?
The incremental build section does not work since as make has been decommissioned in favor of Meson. Should this be simply deleted?
I'd messed up a rebase in my previous iteration, causing `weakly_canonical` to reappear,
but not trigger a test failure.
These two functions behave similarly when the argument is a path that points to a broken
symlink. `weakly_canonical` would not resolve it because the target doesn't exist, and
`makeParentCanonical` would not resolve it, because it never resolves the final path
element.
This new test case now also tests a valid symlink, "differentiating" the two.
The experimental `nix eval` command already supports a `--raw` flag.
This commit implements the same flag for the stable nix-instantiate command.
Until now instructions and scripts that didn't want to rely on experimental
features had to use workarounds such as:
nix-instantiate --eval <something> | tr -d \"
(which also undesirably also removes double quotation marks within the string), or
nix-instantiate --eval <something> | jq -j
(which undesirably depends on another package).
Co-authored-by: Silvan Mosberger <silvan.mosberger@tweag.io>
Upstream change
bab1d75079
moved a few fields from `lowdown_opts` toa new `lowdown_opts_term`
struct. As a result the build started failing as:
nix-cmd> [2/17] Compiling C++ object libnixcmd.so.p/markdown.cc.o
nix-cmd> FAILED: libnixcmd.so.p/markdown.cc.o
nix-cmd> g++ -Ilibnixcmd.so.p -I. -I.. -I/nix/store/b0bnrk5lacxbpgxgnc28r8q3wcazrgxj-nix-util-2.26.0pre-dev/include/nix -I/nix/store/cxnynq9ykyj4xxv6wf6dw7r0aw5x6n9k-libarchive-3.7.7-dev/include -I/nix/store/bfgjwkcb8snkizx578rzdahi75m8zyh4-nlohmann_json-3.11.3/include -I/nix/store/3sx8bq3sip6j2nv1m5xx4gbdp33v7iy6-nix-store-2.26.0pre-dev/include/nix -I/nix/store/sih2dgqzvsbv7p510lkfmas7s7wbsl4j-nix-fetchers-2.26.0pre-dev/include/nix -I/nix/store/68p8s20fsiiakj7nys7grbaixfnhsdzs-nix-expr-2.26.0pre-dev/include/nix -I/nix/store/gw7wknhzhfzzj9zww2kyi5xrzgf1ndki-boehm-gc-8.2.8-dev/include -I/nix/store/3jwb9j4vnsk5saq3wfyyp9il3mhs41l9-nix-flake-2.26.0pre-dev/include/nix -I/nix/store/8nwjvmq7m48v8g646jrxkikv6x47bc3m-nix-main-2.26.0pre-dev/include/nix -I/nix/store/rb0hzsw5wc1a7daizhpj824mbxlvijrq-lowdown-1.4.0-dev/include -I/nix/store/m388ywpk53fsp8r98brfd7nf1f5sskv0-editline-1.17.1-dev/include -fdiagnostics-color=always -D_GLIBCXX_ASSERTIONS=1 -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -std=c++2a -include config-util.hh -include config-store.hh -include config-expr.hh -include config-main.hh -include config-cmd.hh -Wdeprecated-copy -Werror=suggest-override -Werror=switch -Werror=switch-enum -Werror=unused-result -Wignored-qualifiers -Wimplicit-fallthrough -Wno-deprecated-declarations -O3 -fPIC -pthread -std=c++2a -std=c++2a -std=c++2a -std=c++2a -std=c++2a -std=c++2a -MD -MQ libnixcmd.so.p/markdown.cc.o -MF libnixcmd.so.p/markdown.cc.o.d -o libnixcmd.so.p/markdown.cc.o -c ../markdown.cc
nix-cmd> ../markdown.cc: In function 'std::string nix::doRenderMarkdownToTerminal(std::string_view)':
nix-cmd> ../markdown.cc:28:5: error: 'lowdown_opts' has no non-static data member named 'cols'
nix-cmd> 28 | };
nix-cmd> | ^
The change adds version-based conditional to support both pre-1.4 and
1.4 forms of the initialization.
Closes: https://github.com/NixOS/nix/issues/12113
The primitive `readFileType p` has a list of acceptable types, and so does `readDir path`
This edit makes the formatting of the list consistent between themselves, and other parts of the documentation.
Paths are already quoted:
error:
… while fetching the input 'path:/nix/store/rs2s2ca7xs87v82aps54m1p3sqrfz6c8-source'
error: chmod '"/nix/store/rs2s2ca7xs87v82aps54m1p3sqrfz6c8-source"': Read-only file system
src/nix/flake.md describes the format of flake.lock files. Before this
change, it said that the original field was “The original input
specification from `flake.lock`[…]” The original input specification is
in flake.nix, not flake.lock.
When resolving indirect flake references like `nixpkgs` in `flake.nix`
files, Nix will no longer use the system and user flake registries. It
will only use the global flake registry and overrides given on the
command line via `--override-flake`.
Just now there is a dependency on cachix, which means we cannot test
the installer in CI if forks do not have the necessary secrets set up.
We replace this with a simple http server that serves the installer and
can be both used in CI and locally.
Commit cfe66dbec updated `nix upgrade-nix` to use
`ExecutablePath::load().find`, which broke the logic for finding the
profile associated with the nix executable. The error looks something
like:
```
$ sudo -i nix upgrade-nix --debug
found Nix in '"/nix/store/46p1z0w9ad605kky62dr53z4h24k2a5r-nix-2.25.2/bin/nix"'
found profile '/nix/store/46p1z0w9ad605kky62dr53z4h24k2a5r-nix-2.25.2/bin'
error: directory '"/nix/store/46p1z0w9ad605kky62dr53z4h24k2a5r-nix-2.25.2/bin/nix"' does not appear to be part of a Nix profile
```
This seems to happen for two reasons:
1. The original PATH search resulted in a directory, but `find` returns
the path to the executable. Fixed by getting the path's parent.
2. The profile symlink cannot be found because
`ExecutablePath::load().find` canonicalizes the executable path. I
updated find to normalize the path instead, which seems more in line
with how other programs resolve paths. I'm not sure if this affects
other callers though.
I manually tested this on macOS and Linux, and it seemed to fix
upgrading from 2.25.2 to 2.25.3.
- This speeds up macOS builds from 30 minutes to 11 minutes (3x faster).
- Also improve error reporting e.g. printing out what actually failed to build.
- As a result we also no longer need swap.
As far as I can tell, there's no real reason either of these need to
be 664. I'm willing to bet they were just a typo that has lasted for
7 years. While this shouldn't change anything, this is, IMHO, more
correct, so let's stop perpetuating the wrong mode!
We're not testing against these versions anymore.
If we bring that back (I would support that), we could do so in a clean
way, by making sure that the packaging we test against has a proper version
attribute.
Fix a footgun. In my case, I had a couple of build ("output")
directories sitting around.
rm -rf build-*
Was confused for a bit why a meson.build file was missing.
Probably also helps with autocompletion.
I tried meson-build-support first, but I had to add something like
a nix- prefix, in order to make meson happy. They've reserved the
meson- prefix.
I think I have failed to read the very long version-garbage-like
string for the second time now, leaving me oblivious to the crucial
info that a test failure happens in the context of an older daemon.
Before this change, expressions like:
with import <nixpkgs> {};
runCommand "foo" {} ''
echo '@nix {}' >&$NIX_LOG_FD
''
would result in Lix crashing, because accessing nonexistent fields of
a JSON object throws an exception.
Rather than handling each field individually, we just catch JSON
exceptions wholesale. Since these log messages are an unusual
circumstance, log a warning when this happens.
Fixes#544.
Change-Id: Idc2d8acf6e37046b3ec212f42e29269163dca893
(cherry picked from commit e55cd3beea710db727fd966f265a1b715b7285f3)
The Determinate Nix Installer has set nosuid and noatime in https://github.com/DeterminateSystems/nix-installer/pull/1338, and figured this perf and security improvement is worthy of upstreaming.
The /nix volume shouldn't have setuid binaries anyway, and filesystems seem to generally be noatime on macOS.
Further, the garbage collector doesn't use atime.
Instead of the unhelpful
warning: 'https://cache.flakehub.com' does not appear to be a binary cache
you now get
warning: unable to download 'https://cache.flakehub.com/nix-cache-info': HTTP error 401
response body:
{"code":401,"error":"Unauthorized","message":"Unauthorized."}
We *could* use a "native" manual instead - ie reusing a native
`nixpkgsFor.${buildPlatform}`, but this works, and also
works for possible cases where we have a custom or patched build tool.
Without the change `meson setup` fails on `Gentoo or Debian as those
don't use multicall binary:
$ meson setup ..
...
Executing subproject nix-functional-tests
...
../src/nix-functional-tests/meson.build:24:14: ERROR: Program 'coreutils' not found or not executable
The change always uses `ls` to look `coreutils` up.
Closes: https://github.com/NixOS/nix/issues/11975
Upstream `bzip2` does not provide `pkg-config` files. As a result an
attempt to build `nix` on some distributions like Gentoo failos the
configure as:
$ meson setup ..
...
Executing subproject perl
...
perl| Run-time dependency bzip2 found: NO (tried pkgconfig and cmake)
../src/perl/meson.build:68:12: ERROR: Dependency "bzip2" not found, tried pkgconfig and cmake
The change falls back to `bz2` library for such cases.
This prevents any potential cases of deletion through base pointer and its
non-virtual dtor, which might leak memory. Also gets rid of the warning:
/nix/store/fg7ass3a5m5pgl26qzfdniicbwbgzccy-gcc-13.2.0/include/c++/13.2.0/bits/stl_construct.h:88:2: warning: destructor called on non-final 'nix::flake::Settings' that has virtual functions but non-virtual destructor [-Wdelete-non-abstract-non-virtual-dtor]
88 | __location->~_Tp();
....
../src/libflake-c/nix_api_flake.cc:10:30: note: in instantiation of function template specialization 'nix::make_ref<nix::flake::Settings>' requested here
10 | auto settings = nix::make_ref<nix::flake::Settings>();
This gets rid of unnecessary copies in range-based-for loops and
local variables, when they are used solely as `const &`.
Also added a fixme comment about a suspicious move out of const,
which might not be intended.
This shuts up a 300-line warning that includes
/nix/store/fg7ass3a5m5pgl26qzfdniicbwbgzccy-gcc-13.2.0/include/c++/13.2.0/bits/stl_tree.h:182:25: warning: ‘*(std::_Rb_tree_header*)((char*)&<unnamed> + offsetof(nix::value_type, nix::DerivedPath::<unnamed>.std::variant<nix::DerivedPathOpaque, nix::DerivedPathBuilt>::<unnamed>.std::__detail::__variant::_Variant_base<nix::DerivedPathOpaque, nix::DerivedPathBuilt>::<unnamed>.std::__detail::__variant::_Move_assign_base<false, nix::DerivedPathOpaque, nix::DerivedPathBuilt>::<unnamed>.std::__detail::__variant::_Copy_assign_base<false, nix::DerivedPathOpaque, nix::DerivedPathBuilt>::<unnamed>.std::__detail::__variant::_Move_ctor_base<false, nix::DerivedPathOpaque, nix::DerivedPathBuilt>::<unnamed>.std::__detail::__variant::_Copy_ctor_base<false, nix::DerivedPathOpaque, nix::DerivedPathBuilt>::<unnamed>.std::__detail::__variant::_Variant_storage<false, nix::DerivedPathOpaque, nix::DerivedPathBuilt>::_M_u) + 24).std::_Rb_tree_header::_M_header.std::_Rb_tree_node_base::_M_parent’ may be used uninitialized [-Wmaybe-uninitialized]
182 | if (__x._M_header._M_parent != nullptr)
| ~~~~~~~~~~~~~~^~~~~~~~~
Since lib{expr,store,util}-test-support subprojects define nix_api_* helpers
for testing nix c bindings, they need to publicly depend on -c counterparts.
This makes their headers self-sufficient and does not rely on the -tests to add
necessary dependencies.
Get rid of this fixme. This does not appear to be used anywhere in
the nix codebase itself. Not sure why the comment mentioned C++20 erase
member function with predicate, but iterator-based algorithms are also fine.
Looks like some cruft has been left over from previous refactorings.
This removes dead variables, which should not have side effects in their
constructors. In cases where the variable initialization has a purpose
[[maybe_unused]] is inserted to silence compiler warnings.
* doc: Clarify that nix-shell still uses shell from host environment
* doc: Fix NIX_BUILD_SHELL description
* doc: Add anchor and link to NIX_BUILD_SHELL
* doc: Add example of default shell trickiness
Co-authored-by: Valentin Gagarin <valentin@gagarin.work>
This reduces the amount of boilerplate. More importantly, it provides
a place to add compiler flags (such as -O3) without having to add it
to every subproject (and the risk of forgetting to include it).
Fixes
nix: ../src/libexpr/primops/fetchTree.cc:37: void nix::emitTreeAttrs(EvalState&, const StorePath&, const fetchers::Input&, Value&, bool, bool): Assertion `narHash' failed.
on a lock file with an input that doesn't have a narHash. This can
happen when using a lock file created by the lazy-trees branch.
Cherry-picked from lazy-trees.
When diagnosing infinite recursion references to nullptr `Env` can be formed.
This happens only with `ExprBlackHole` is evaluated, which always leads to
`InfiniteRecursionError`.
UBSAN log for one such case:
```
../src/libexpr/eval-inline.hh:94:31: runtime error: reference binding to null pointer of type 'Env'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior ../src/libexpr/eval-inline.hh:94:31 in
```
First the motivation: I recently faced a bug that I assume is coming
from the topoSortPaths function where the GC was trying to delete a
path having some alive referrers. I resolved this by manually deleting
the faulty path referrers using nix-store --query --referrers. I sadly
did not manage to reproduce this bug.
This bug alone is not a big deal. However, this bug is
triggering a cascading failure: invalidatePathChecked is throwing a
PathInUse exception. This exception is not catched and fails the whole GC
run. From there, the machine (a builder machine) was unable to GC its
Nix store, which led to an almost full disk with no way to
automatically delete the dead Nix paths.
Instead, I think we should log the error for the specific store path
we're trying to delete, specifying we can't delete this path because
it still has referrers. Once we're done with logging that, the GC run
should continue to delete the dead store paths it can delete.
This is the first part of rewriteDerivation() factored out into its
own method. It's not used anywhere else at the moment, but it's useful
on lazy-trees for rewriting virtual paths.
It's not so common knowledge that forges also expose pull requests as
git refs. But it's actually a cool way of quickly testing someones
contribution, so I found it worth specifically mentioning it.
It seems that I copied the expression for baseDir thoughtlessly and
did not come back to it.
- `baseDir` was only used in the `fromArgs` branch.
- `fromArgs` is true when `packages` is true.
This interferes with the progress bar, resulting in output like
evaluating derivation 'git+file:///home/eelco/Dev/nix-master#packages.x86_64-linux.default'/nix/store/zz8v96j5md952x0mxfix12xqnvq5qv5x-nix-2.26.0pre20241114_a95f6ea.drv
This patch gets rid of UB when verbosity exceeds the maximum logging value of `lvlVomit = 7` and
reaches invalid values (e.g. 8). This is actually triggered in functional tests.
There are too many occurrences to list, but here's one from the UBSAN log:
../src/libstore/gc.cc:610:5: runtime error: load of value 8, which is not a valid value for type 'Verbosity'
This was first tagged as 2.15.0, 1½ years ago; plenty of time for
everyone to catch up.
By now, the warning is causing more confusion than that it is helpful,
because passing a `.drv` or `drvPath` has legitimate use cases.
The API docs build is extremely noisy (#11841) and probably not many
people care about it anyway. Also, they get rebuild on *every* ninja
invocation which is generally a waste of time.
Of course, you can still build the docs via `nix build
.#nix-{internal,external}-api-docs`, which is pretty fast.
The new package output attributes are somewhat experimental, and
provided for compatibility most of all.
We'll see how well this goes before the changes proposed in
https://github.com/NixOS/nix/issues/6507
Add options uid, gid, uname, and gname to docker.nix.
Setting these to e.g. 1000, 1000, "user", "user" will build an image
which runs and allows using Nix as that user.
In these trivial cases the final vector size (or lower bound on the size) is known,
so we can avoid some vector reallocations. This is not very important, but is just
good practice and general hygiene.
This is good practice to avoid pessimisations.
Left comments for the reasoning why ctors should be noexcept.
There are some tricky cases where we intentionally want throwing move ctors/assignments.
But those cases should really be reviewed, since some of those can be replaced
with more idiomatic copy/move-and-swap.
`auto &&` and `T &&` are forwarding references and can be
either lvalue or rvalue references. Moving from universal references
is incorrect and should not be done.
Moving from integral or floating-point values is pointless and just
worsens debug performance.
Naming class member variables the same as constructor arguments is a very
slippery slope because of how member variable names get resolved. Compiler
is not very helpful here and we need static analysis to forbid this kind of
stuff.
The following example illustrates the cause quite well:
```cpp
struct B {
B(int) {}
};
struct A {
A(int b): b([&](){
return b;
static_assert(std::is_same_v<decltype(b), int>);
}()) {
static_assert(std::is_same_v<decltype(b), int>);
}
void member() {
static_assert(std::is_same_v<decltype(b), B>);
}
B b;
};
int main() {
A(1).member();
}
```
From N4861 6.5.1 Unqualified name lookup:
> In all the cases listed in [basic.lookup.unqual], the scopes are searched
> for a declaration in the order listed in each of the respective categories;
> name lookup ends as soon as a declaration is found for the name.
> If no declaration is found, the program is ill-formed.
In the affected code there was a use-after-move for all accesses in the constructor
body, but this UB wasn't triggered.
These types of errors are trivial to catch via clang-tidy's [clang-analyzer-cplusplus.Move].
This was broken since a03bb4455c because
Nix 2.18 does not support broken $SHELL settings. So don't try a
broken $SHELL on old Nix versions. (It's a mystery though why
tests.remoteBuilds_local_nix_2_13 and tests.remoteBuilds_local_nix_2_3
didn't fail...)
https://hydra.nixos.org/build/277366807
This may occur when stderr is a tty but stdin is empty.
E.g.
$ nix build </dev/null
error: unexpected EOF reading a line
These stdio handles are how some non-interactive sandboxes behave,
including the Nix build sandbox and Hercules CI Effects.
Unfortunately `StringSource` class is very easy was very easy to misuse
because the ctor took a plain `std::string_view` which has a bad habit
of being implicitly convertible from an rvalue `std::string`. This lead
to unintentional use-after-free bugs.
This patch makes `StringSource` much harder to misuse by disabling the ctor
from a `std::string &&` (but `const std::string &` is ok).
Fix affected tests from libstore-tests.
Reformat those tests with clangd's range formatting since the diff is tiny
and it seems appropriate.
It had gotten rather big. Hopefully we'll eventually have some generic
infra for a "multi-package dev shell" and not need so much code for
this, but until then it's better in a separate file.
operators are an everyday thing in the Nix language, and this page will
hopefully be consulted by many users.
string contexts are quite exotic, and not linking to the detailed
explanation will require readers to figure out manually what this is
about, or worse, skim over and run into problems later.
* doc/manual: Add 'Debugging Nix' section
This commit adds a new 'Debugging Nix' section to the Nix manual. It provides instructions on how to build Nix with debug symbols and how to debug the Nix binary using debuggers like `lldb`.
Co-authored-by: Jörg Thalheim <Mic92@users.noreply.github.com>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
We now just check that the fetcher doesn't change any attributes in
the input, and return all the original attributes (i.e. discarding any
new attributes and keeping any attributes that the fetcher didn't
keep).
This fixes the error
'{"__final":true,"lastModified":1686592866,"narHash":"sha256-riGg89eWhXJcPNrQGcSwTEEm7CGxWC06oSX44hajeMw","owner":"nixos","repo":"nixpkgs","rev":"0eeebd64de89e4163f4d3cf34ffe925a5cf67a05","type":"github"}' resulted in different input
'{"__final":true,"lastModified":1686592866,"narHash":"sha256-riGg89eWhXJcPNrQGcSwTEEm7CGxWC06oSX44hajeMw=","owner":"nixos","repo":"nixpkgs","rev":"0eeebd64de89e4163f4d3cf34ffe925a5cf67a05","type":"github"}'
in flake-regressions/tests/nix-community/patsh/0.2.1 (note the lack of
a trailing '=' in the NAR hash in the lock file).
OpenBSD doesn't support `lutimes`, but does support `utimensat` which
subsumes it. In fact, all the BSDs, Linux, and newer macOS all support
it. So lets make this our first choice for the implementation.
In addition, let's get rid of the `lutimes` `ENOSYS` special case. The
Linux manpage says
> ENOSYS
>
> The kernel does not support this call; Linux 2.6.22 or later is
> required.
which I think is the origin of this check, but that's a very old version
of Linux at this point. The code can be simplified a lot of we drop
support for it here (as we've done elsewhere, anyways).
Co-Authored-By: John Ericson <John.Ericson@Obsidian.Systems>
Backward-compatible schema changes (e.g. those that add tables or
nullable columns) now no longer need a change to the global schema
file (/nix/var/nix/db/schema). Thus, old Nix versions can continue to
access the database.
This is especially useful for schema changes required by experimental
features. In particular, it replaces the ad-hoc handling of the schema
changes for CA derivations (i.e. the file /nix/var/nix/db/ca-schema).
Schema versions 8 and 10 could have been handled by this mechanism in
a backward-compatible way as well.
OpenBSD dynamic libraries never link to libc directly.
Instead, they have undefined symbols for all libc functions they use
that ld.so resolves to the libc referred to in the main executable.
Thus, disallowing undefined symbols will always fail
the default int64_t max was still overflowing for me, when this was dumped as json (noticed during building the manual).
So making 0, the default and define it as "no warnings" fixes the situtation.
Also it's much more human-readable in documentation.
This works because the `builder` and `args` variables are only used
in the non-builtin code path.
Co-Authored-By: Théophane Hufschmitt <theophane.hufschmitt@tweag.io>
tests/functional/help.sh calls nix-* commands with option --help
if nix is built without documentation the option --help throws an error
because the man page it wants to display is missing
This overall seems like insecure tmp file handling to me. Because other
users could replace files in /tmp with a symlink and make the nix-shell
override other files.
fixes https://github.com/NixOS/nix/issues/11470
Introduced in 8f6b347abd without explanation.
Throwing anything that's not that is a programming mistake that we don't want
to ignore silently. A crash would be ok, because that means we/they can fix
the offending throw.
Otherwise, if checkInterrupt() in any of the supported store operations
would catch onto a user interrupt, the exception would bubble to the thread
start and be handled by std::terminate(): a crash.
We haven't added the narHash attribute yet at that point. And if the
caller uses getAccesor() instead of fetchToStore() (e.g. in `nix
registry pin`), the narHash attribute will never be added. This could
lead to a mismatch.
The ability to substitute inputs was removed in #10612 because it was
broken: with user-specified inputs containing a `narHash` attribute,
substitution resulted in an input that lacked the attributes returned
by the real fetcher (such as `lastModified`).
To fix this, we introduce a new input attribute `final`. If `final =
true`, fetching the input cannot add or change any attributes.
We only attempt to substitute inputs that have `final = true`. This is
implied by lock file entries; we only write a lock file if all its
entries are "final".
The user can specified `final = true` in `fetchTree`, in which case it
is their responsibility to ensure that all attributes returned by the
fetcher are included in the `fetchTree` call. For example,
nix eval --impure --expr 'builtins.fetchTree { type = "github"; owner = "NixOS"; repo = "patchelf"; final = true; narHash = "sha256-FSoxTcRZMGHNJh8dNtKOkcUtjhmhU6yQXcZZfUPLhQM="; }'
succeeds in a store path with the specified NAR hash exists or is
substitutable, but fails with
error: fetching final input '{"final":true,"narHash":"sha256-FSoxTcRZMGHNJh8dNtKOkcUtjhmhU6yQXcZZfUPLhQM=","owner":"NixOS","repo":"patchelf","type":"github"}' resulted in different input '{"final":true,"lastModified":1718457448,"narHash":"sha256-FSoxTcRZMGHNJh8dNtKOkcUtjhmhU6yQXcZZfUPLhQM=","owner":"NixOS","repo":"patchelf","rev":"a0f54334df36770b335c051e540ba40afcbf8378","type":"github"}'
... and remove a few unused arguments.
This adds pkg-config to a two or three packages that don't use it,
but we shouldn't let that bother us. It's like our personal stdenv.
If you have the Nix store mounted from a nonlocal filesystem whose
exporter is not running as root, making the directory mode 000 makes it
inaccessible to that remote unprivileged user and therefore breaks the
build. (Specifically, I am running into this with a virtiofs mount using
Apple Virtualization.framework as a non-root user, but I expect the
same thing would happen with virtiofs in qemu on Linux as a non-root
user or with various userspace network file servers.)
Make the directory mode 500 (dr-x------) to make the sandbox work in
this use case, which explicitly conveys our intention to read and search
the directory. The code only works because root can already bypass
directory checks, so this does not actually grant more permissions to
the directory owner / does not make the sandbox less secure.
This allows `nix copy` to atomically copy a store path and point a
profile to it, without the risk that the store path might be GC'ed in
between. This is useful for instance when deploying a new NixOS system
profile from a remote store.
This caused nlohmann/json.hpp to leak into a lot of compilation units,
which is slow (when not using precompiled headers).
Cuts build time from 46m24s to 42m5s (real time with -j24: 2m42s to
2m24s).
These versions are more than 3 years old and were very early in the
existence of CA derivations support (which was and is experimental),
so they're unlikely to still exist in the real world. So let's get rid
of support for them.
The previous documentation was inaccurate, stating that it would not update existing inputs. However these inputs will be updated if they are outdated (for example the version of an existing input has been changed). The new text properly reflects this behaviour.
A test added recently checks that when trying to deserialize a NAR with
two files that Unicode-normalize to the same result either succeeds on
Linux, or fails with an "already exists" error on Darwin. However,
failing with an "already exists" error can in fact also happen on Linux,
when using ZFS with the proper utf8 and Unicode normalization options
set.
This commit fixes the issue by not assuming the behavior from the
current system, but just by blindly checking that either one of the two
aforementioned possibilities happen, whether on Darwin or on Linux.
Additionally, we check that the Unicode normalization behaviour of
nix-store is the same as the host file system.
This leads to confusion about what the command does.
E.g. https://github.com/NixOS/nix/issues/9359
- Move the description up
- Remove details about the individual formatters
This patch has been manually adapted from
14dc84ed03
Tested with:
$ NIX_SSL_CERT_FILE=$(nix-build '<nixpkgs>' -A cacert)/etc/ssl/certs/ca-bundle.crt nix-build --store $(mktemp -d) -E 'import <nix/fetchurl.nix> { url = https://google.com; }'
Finished at 16:57:50 after 1s
warning: found empty hash, assuming 'sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA='
this derivation will be built:
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
google.com> building '/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv'
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
google.com> error:
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
google.com> … writing file '/nix/store/0zynn4n8yx59bczy1mgh1lq2rnprvvrc-google.com'
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
google.com>
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
google.com> error: unable to download 'https://google.com': Problem with the SSL CA cert (path? access rights?) (77) error setting certificate file: /nix/store/nlgbippbbgn38hynjkp1ghiybcq1dqhx-nss-cacert-3.101.1/etc/ssl/certs/ca-bundle.crt
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
error: builder for '/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv' failed with exit code 1
Now returns:
nix-env % NIX_SSL_CERT_FILE=$(nix-build '<nixpkgs>' -A cacert)/etc/ssl/certs/ca-bundle.crt nix-build --store $(mktemp -d) -E 'import <nix/fetchurl.nix> { url = https://google.com; }'
Finished at 17:05:48 after 0s
warning: found empty hash, assuming 'sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA='
this derivation will be built:
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
google.com> building '/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv'
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
nix-output-monitor error: DerivationReadError /nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv: openFile: does not exist (No such file or directory)
error: hash mismatch in fixed-output derivation '/nix/store/4qljhy0jj2b0abjzpsbyarpia1bqylwc-google.com.drv':
specified: sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
This method is marked as `noexcept`, but `enqueueFileTransfer()` can
throw `Interrupted` if the user has hit Ctrl-C or if the `ThreadPool`
that the thread is a part of is shutting down.
When working on speeding up the CI,
I triggered a race condition in the creation of the tarball cache.
This code now instead will ensure that half-initialized repositories
are no longer visible to any other nix process.
This is the error message that I got before:
error: opening Git repository '"/Users/runner/.cache/nix/tarball-cache"': could not find repository at '/Users/runner/.cache/nix/tarball-cache'
* docs: specify that flake.lock files are JSON
Recently, I decided that I was going to write some code that would parse
flake.lock files. I went to the Nix Reference Manual in order to look up
information on the format of flake.lock files, and I realized that a key
detail was missing from the Nix Reference Manual: it never says that
flake.lock files are JSON files. This commit fixes that issue.
This commit makes sure to specify that flake.lock files are encoded in
UTF-8. Confusingly, there’s multiple different JSON standards. Neither
ECMA-404, 2nd Edition [1] nor ISO/IEC 21778:2017 [2] mention UTF-8. RFC
8259 requires UTF-8, but only sometimes [3]. I chose to explicitly
specify that flake.lock files are UTF-8 in order to avoid any possible
ambiguities from the JSON standards.
[1]: <https://ecma-international.org/publications-and-standards/standards/ecma-404>
[2]: <https://www.iso.org/standard/71616.html>
[3]: <https://www.rfc-editor.org/rfc/rfc8259.html#section-8.1>
Most of the time people run single tests for debugging reason,
so it's a sane default to have them see all the console output.
This commit still retains the section about running tests directly with
meson, because in some debugging cases it's just nice to have less
abstractions i.e. when using strace.
Since #8766, invalid base64 is rendered in errors, but we don't actually
want to show this in the case of an invalid private keys.
Co-Authored-By: Eelco Dolstra <edolstra@gmail.com>
This is better for privacy and to avoid leaking netrc credentials in a
MITM attack, but also the assumption that we check the hash no longer
holds in some cases (in particular for impure derivations).
Partially reverts 5db358d4d7.
As a prelude to making "or" work like a normal variable, emit a warning
any time the "fn or" production is used in a context that will change
how it is parsed when that production is refactored.
In detail: in the future, OR_KW will be moved to expr_simple, and the
cursed ExprCall production that is currently part of the expr_select
nonterminal will be generated "normally" in expr_app instead. Any
productions that accept an expr_select will be affected, except for the
expr_app nonterminal itself (because, while expr_app has a production
accepting a bare expr_select, its other production will continue to
accept "fn or" expressions). So all we need to do is emit an appropriate
warning when an expr_simple representing a cursed ExprCall is accepted
in one of those productions without first going through expr_app.
As the warning message describes, users can suppress the warning by
wrapping their problematic "fn or" expressions in parentheses. For
example, "f g or" can be made future-proof by rewriting it as
"f (g or)"; similarly "[ x y or ]" can be rewritten as "[ x (y or) ]",
etc. The parentheses preserve the current grouping behavior, as in the
future "f g or" will be parsed as "(f g) or", just like
"f g anything-else" is grouped. (Mechanically, this suppresses the
warning because the problem ExprCalls go through the
"expr_app : expr_select" production, which resets the cursed status on
the ExprCall.)
Subflakes are flakes in the same tree, accessed in flake inputs via
relative paths (e.g. `inputs.foo.url = "path:./subdir"`). Previously
these didn't work very well because they would be separately copied to
the store, which is inefficient and makes references to parent
directories tricky or impossible. Furthermore, they had their own NAR
hash in the lock file, which is superfluous since the parent is
already locked.
Now subflakes are accessed via the accessor of the calling flake. This
avoids the unnecessary copy and makes it possible for subflakes to
depend on flakes in a parent directory (so long as they're in the same
tree).
Lock file nodes for relative flake inputs now have a new `parent` field:
{
"locked": {
"path": "./subdir",
"type": "path"
},
"original": {
"path": "./subdir",
"type": "path"
},
"parent": [
"foo",
"bar"
]
}
which denotes that `./subdir` is to be interpreted relative to the
directory of the `bar` input of the `foo` input of the root flake.
Extracted from the lazy-trees branch.
- To remove the stale label, just leave a new comment.
- _How to find the right people to ping?_ → [`git blame`](https://git-scm.com/docs/git-blame) to the rescue! (or GitHub's history and blame buttons.)
- You can always ask for help on [our Discourse Forum](https://discourse.nixos.org/) or on [Matrix - #nix:nixos.org](https://matrix.to/#/#nix:nixos.org).
- You can always ask for help on [our Discourse Forum](https://discourse.nixos.org/) or on [Matrix - #users:nixos.org](https://matrix.to/#/#users:nixos.org).
- run:nix --experimental-features 'nix-command flakes' flake show --all-systems --json
# Steps to test CI automation in your own fork.
# Cachix:
# 1. Sign-up for https://www.cachix.org/
# 2. Create a cache for $githubuser-nix-install-tests
# 3. Create a cachix auth token and save it in https://github.com/$githubuser/nix/settings/secrets/actions in "Repository secrets" as CACHIX_AUTH_TOKEN
# Dockerhub:
# 1. Sign-up for https://hub.docker.com/
# 2. Store your dockerhub username as DOCKERHUB_USERNAME in "Repository secrets" of your fork repository settings (https://github.com/$githubuser/nix/settings/secrets/actions)
# 3. Create an access token in https://hub.docker.com/settings/security and store it as DOCKERHUB_TOKEN in "Repository secrets" of your fork
check_secrets:
permissions:
contents:none
name:Check Cachix and Docker secrets present for installer tests
# 2. Store your dockerhub username as DOCKERHUB_USERNAME in "Repository secrets" of your fork repository settings (https://github.com/$githubuser/nix/settings/secrets/actions)
# 3. Create an access token in https://hub.docker.com/settings/security and store it as DOCKERHUB_TOKEN in "Repository secrets" of your fork
check_secrets:
permissions:
contents:none
name:Check Docker secrets present for installer tests
@@ -31,7 +31,7 @@ Today, a world-wide developer community contributes to Nix and the ecosystem tha
- [Nixpkgs](https://github.com/NixOS/nixpkgs) is [the largest, most up-to-date free software repository in the world](https://repology.org/repositories/graphs)
- [NixOS](https://github.com/NixOS/nixpkgs/tree/master/nixos) is a Linux distribution that can be configured fully declaratively
- [Discourse](https://discourse.nixos.org/)
-[Matrix](https://matrix.to/#/#nix:nixos.org)
- Matrix: [#users:nixos.org](https://matrix.to/#/#users:nixos.org) for user support and [#nix-dev:nixos.org](https://matrix.to/#/#nix-dev:nixos.org) for development
[test "$ENABLE_BUILD" == "no" && test "$ENABLE_UNIT_TESTS" == "yes"],
[AC_MSG_ERROR([Cannot enable unit tests when building overall is disabled. Please do not pass '--enable-unit-tests' or do not pass '--disable-build'.])])
AC_ARG_ENABLE(functional-tests, AS_HELP_STRING([--disable-functional-tests],[Do not build the tests]),
[test "$ENABLE_BUILD" == "no" && test "$ENABLE_DOC_GEN" == "yes"],
[AC_MSG_ERROR([Cannot enable generated docs when building overall is disabled. Please do not pass '--enable-doc-gen' or do not pass '--disable-build'.])])
AS_IF(
[test "$ENABLE_FUNCTIONAL_TESTS" == "yes" || test "$ENABLE_DOC_GEN" == "yes"],
[NEED_PROG(jq, jq)])
AS_IF([test "$ENABLE_BUILD" == "yes"],[
# Look for boost, a required dependency.
# Note that AX_BOOST_BASE only exports *CPP* BOOST_CPPFLAGS, no CXX flags,
# and CPPFLAGS are not passed to the C++ compiler automatically.
# Thus we append the returned CPPFLAGS to the CXXFLAGS here.
AS_HELP_STRING([--disable-cpuid], [Do not determine microarchitecture levels with libcpuid (relevant to x86_64 only)]))
if test "x$enable_cpuid" != "xno"; then
PKG_CHECK_MODULES([LIBCPUID], [libcpuid],
[CXXFLAGS="$LIBCPUID_CFLAGS $CXXFLAGS"
have_libcpuid=1
AC_DEFINE([HAVE_LIBCPUID], [1], [Use libcpuid])]
)
fi
fi
AC_SUBST(HAVE_LIBCPUID, [$have_libcpuid])
# Look for libseccomp, required for Linux sandboxing.
case "$host_os" in
linux*)
AC_ARG_ENABLE([seccomp-sandboxing],
AS_HELP_STRING([--disable-seccomp-sandboxing],[Don't build support for seccomp sandboxing (only recommended if your arch doesn't support libseccomp yet!)
]))
if test "x$enable_seccomp_sandboxing" != "xno"; then
synopsis: Use envvars NIX_CACHE_HOME, NIX_CONFIG_HOME, NIX_DATA_HOME, NIX_STATE_HOME if defined
prs: [11351]
---
Added new environment variables:
-`NIX_CACHE_HOME`
-`NIX_CONFIG_HOME`
-`NIX_DATA_HOME`
-`NIX_STATE_HOME`
Each, if defined, takes precedence over the corresponding [XDG environment variable](@docroot@/command-ref/env-common.md#xdg-base-directories).
This provides more fine-grained control over where Nix looks for files, and allows to have a stand-alone Nix environment, which only uses files in a specific directory, and doesn't interfere with the user environment.
synopsis: Define integer overflow in the Nix language as an error
issues: [10968]
prs: [11188]
---
Previously, integer overflow in the Nix language invoked C++ level signed overflow, which was undefined behaviour, but *usually* manifested as wrapping around on overflow.
Since prior to the public release of Lix, Lix had C++ signed overflow defined to crash the process and nobody noticed this having accidentally removed overflow from the Nix language for three months until it was caught by fiddling around.
Given the significant body of actual Nix code that has been evaluated by Lix in that time, it does not appear that nixpkgs or much of importance depends on integer overflow, so it appears safe to turn into an error.
Some other overflows were fixed:
-`builtins.fromJSON` of values greater than the maximum representable value in a signed 64-bit integer will generate an error.
-`nixConfig` in flakes will no longer accept negative values for configuration options.
Integer overflow now looks like the following:
```
$ nix eval --expr '9223372036854775807 + 1'
error: integer overflow in adding 9223372036854775807 + 1
synopsis: "`build-cores = 0` now auto-detects CPU cores"
prs: [13402]
---
When `build-cores` is set to `0`, nix now automatically detects the number of available CPU cores and passes this value via `NIX_BUILD_CORES`, instead of passing `0` directly. This matches the behavior when `build-cores` is unset. This prevents the builder from having to detect the number of cores.
The `build-hook` setting's default is less useful when using `libnixstore` as a library
prs:
- 11178
---
*This is an obscure issue that only affects usage of the `libnixstore` library outside of the Nix executable.*
As part the ongoing [rewrite of the build system](https://github.com/NixOS/nix/issues/2503) to use [Meson](https://mesonbuild.com/), we are also switching to packaging individual Nix components separately (and building them in separate derivations).
This means that when building `libnixstore` we do not know where the Nix binaries will be installed --- `libnixstore` doesn't know about downstream consumers like the Nix binaries at all.
*This is also unrelated to the _`post`_-`build-hook`*, which is often used for pushing to a cache.*
This has a small adverse affect on remote building --- the `build-remote` executable that is specified from the [`build-hook`](@docroot@/command-ref/conf-file.md#conf-build-hook) setting will not be gotten from the (presumed) installation location, but instead looked up on the `PATH`.
This means that other applications linking `libnixstore` that wish to use remote building must arrange for the `nix` command to be on the PATH (or manually overriding `build-hook`) in order for that to work.
Long term we don't envision this being a downside, because we plan to [get rid of `build-remote` and the build hook setting entirely](https://github.com/NixOS/nix/issues/1221).
There is simply no need to add a second layer of remote-procedure-calling when we want to connect to a remote builder.
The build hook protocol did in principle support custom ways of remote building, but that can also be accomplished with a custom service for the ssh or daemon/ssh-ng protocols, or with a custom [store type](@docroot@/store/types/index.md) i.e. `Store` subclass. <!-- we normally don't mention classes, but consider that this release note is about a library use case -->
The Perl bindings no longer expose `getBinDir` either, since they libraries those bindings wrap no longer know the location of installed binaries as described above.
synopsis: wrap filesystem exceptions more correctly
issues: []
prs: [11378]
---
With the switch to `std::filesystem` in different places, Nix started to throw `std::filesystem::filesystem_error` in many places instead of its own exceptions.
This lead to no longer generating error traces, for example when listing a non-existing directory, and can also lead to crashes inside the Nix REPL.
This version catches these types of exception correctly and wrap them into Nix's own exeception type.
Nix now has a setting `fsync-store-paths` that ensures that new store paths are durably written to disk before they are registered as "valid" in Nix's database. This can prevent Nix store corruption if the system crashes or there is a power loss. This setting defaults to `false`.
synopsis: Show package descriptions with `nix flake show`
issues: [10977]
prs: [10980]
---
`nix flake show` will now display a package's `meta.description` if it exists. If the description does not fit in the terminal it will be truncated to fit the terminal width. If the size of the terminal width is unknown the description will be capped at 80 characters.
Nix will no longer attempt to substitute the source code of flakes from a binary cache. This functionality was broken because it could lead to different evaluation results depending on whether the flake was available in the binary cache, or even depending on whether the flake was already in the local store.
A local Nix installation can forward Nix builds to other machines,
this allows multiple builds to be performed in parallel.
Remote builds also allow Nix to perform multi-platform builds in a
semi-transparent way. For example, if you perform a build for a
`x86_64-darwin` on an `i686-linux` machine, Nix can automatically
forward the build to a `x86_64-darwin` machine, if one is available.
## Requirements
For a local machine to forward a build to a remote machine, the remote machine must:
- Have Nix installed
- Be running an SSH server, e.g. `sshd`
- Be accessible via SSH from the local machine over the network
- Have the local machine's public SSH key in `/etc/ssh/authorized_keys.d/<username>`
- Have the username of the SSH user in the `trusted-users` setting in `nix.conf`
## Testing
To test connecting to a remote [Nix instance] (in this case `mac`), run:
```console
nix store info --store ssh://username@mac
```
To specify an SSH identity file as part of the remote store URI add a
query parameter, e.g.
```console
nix store info --store ssh://username@mac?ssh-key=/home/alice/my-key
```
Since builds should be non-interactive, the key should not have a
passphrase. Alternatively, you can load identities ahead of time into
`ssh-agent` or `gpg-agent`.
In a multi-user installation (default), builds are executed by the Nix
Daemon. The Nix Daemon cannot prompt for a passphrase via the terminal
or `ssh-agent`, so the SSH key must not have a passphrase.
In addition, the Nix Daemon's user (typically root) needs to have SSH
access to the remote builder.
Access can be verified by running `sudo su`, and then validating SSH
access, e.g. by running `ssh mac`. SSH identity files for root users
are usually stored in `/root/.ssh/` (Linux) or `/var/root/.ssh` (MacOS).
If you get the error
```console
bash: nix: command not found
error: cannot connect to 'mac'
```
then you need to ensure that the `PATH` of non-interactive login shells
contains Nix.
The [list of remote build machines](@docroot@/command-ref/conf-file.md#conf-builders) can be specified on the command line or in the Nix configuration file.
For example, the following command allows you to build a derivation for `x86_64-darwin` on a Linux machine:
@@ -53,6 +53,11 @@ This command has the following operations:
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.
> **Note**
>
> Downloaded channel contents are cached.
> Use `--tarball-ttl` or the [`tarball-ttl` configuration option](@docroot@/command-ref/conf-file.md#conf-tarball-ttl) to change the validity period of cached downloads.
- `--list-generations`
Prints a list of all the current existing generations for the
@@ -36,7 +36,7 @@ Instead, it looks in a few locations, and acts on all profiles it finds there:
>
> Not stable; subject to change
>
> Do not rely on this functionality; it just exists for migration purposes and is may change in the future.
> Do not rely on this functionality; it just exists for migration purposes and 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`.
@@ -62,6 +62,15 @@ These options are for deleting old [profiles] prior to deleting unreachable [sto
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.
<!-- duplication from https://github.com/NixOS/nix/blob/442a2623e48357ff72c77bb11cf2cf06d94d2f90/doc/manual/source/command-ref/nix-store/gc.md?plain=1#L39-L44 -->
Keep deleting paths until at least *bytes* bytes have been deleted,
then stop. The argument *bytes* can be followed by the
@@ -62,7 +62,7 @@ These pages can be viewed offline:
Several operations, such as [`nix-env --query`](./nix-env/query.md) and [`nix-env --install`](./nix-env/install.md), take a list of *arguments* that specify the packages on which to operate.
Packages are identified based on a `name` part and a `version` part of a [symbolic derivation name](@docroot@/language/derivations.md#attr-names):
Packages are identified based on a `name` part and a `version` part of a [symbolic derivation name](@docroot@/language/derivations.md#attr-name):
- `name`: Everything up to but not including the first dash (`-`) that is *not* followed by a letter.
- `version`: The rest, excluding the separating dash.
@@ -21,11 +22,11 @@ It is based on the current generation of the active [profile](@docroot@/command-
The arguments *args* map to store paths in a number of possible ways:
- By default, *args* is a set of [derivation] names denoting derivations in the [default Nix expression].
- By default, *args* is a set of names denoting derivations in the [default Nix expression].
These are [realised], and the resulting output paths are installed.
Currently installed derivations with a name equal to the name of a derivation being added are removed unless the option `--preserve-installed` is specified.
@@ -61,11 +62,15 @@ The arguments *args* map to store paths in a number of possible ways:
The derivations returned by those function calls are installed.
This allows derivations to be specified in an unambiguous way, which is necessary if there are multiple derivations with the same name.
- If *args* are [store derivations](@docroot@/glossary.md#gloss-store-derivation), then these are [realised], and the resulting output paths are installed.
- If `--priority`*priority* is given, the priority of the derivations being installed is set to *priority*.
This can be used to override the priority of the derivations being installed.
This is useful if *args* are [store paths], which don't have any priority information.
- If *args* are [store paths] that are not store derivations, then these are [realised] and installed.
- If *args* are [store paths] that point to [store derivations][store derivation], then those store derivations are [realised], and the resulting output paths are installed.
- By default all [outputs](@docroot@/language/derivations.md#attr-outputs) are installed for each [derivation].
- If *args* are [store paths] that do not point to store derivations, then these are [realised] and installed.
- By default all [outputs](@docroot@/language/derivations.md#attr-outputs) are installed for each [store derivation].
This can be overridden by adding a `meta.outputsToInstall` attribute on the derivation listing a subset of the output names.
Example:
@@ -117,6 +122,8 @@ The arguments *args* map to store paths in a number of possible ways:
The operation `--add` adds the specified paths to the Nix store. It
prints the resulting paths in the Nix store on standard output.
*paths* that refer to symlinks are not dereferenced, but added to the store
as symlinks with the same target.
{{#include ./opt-common.md}}
{{#include ../opt-common.md}}
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