packaging: Fix static builds with S3 support, enable by default

aws-crt-cpp doesn't provide pkg-config files and has a bunch of transitive
deps, so switch to cmake for resolving the dependency.

src/libstore/meson.build

@@ -158,14 +158,15 @@ sqlite = dependency('sqlite3', 'sqlite', version : '>=3.6.19')
 deps_private += sqlite
 
 s3_aws_auth = get_option('s3-aws-auth')
-aws_crt_cpp = cxx.find_library('aws-crt-cpp', required : s3_aws_auth)
+aws_crt_cpp = dependency(
+  'aws-crt-cpp',
+  required : s3_aws_auth,
+  method : 'cmake',
+  modules : [ 'AWS::aws-crt-cpp' ],
+)
 
 if s3_aws_auth.enabled()
   deps_other += aws_crt_cpp
-  aws_c_common = cxx.find_library('aws-c-common', required : true)
-  deps_other += aws_c_common
-  aws_c_auth = cxx.find_library('aws-c-auth', required : true)
-  deps_other += aws_c_auth
 endif
 
 configdata_pub.set('NIX_WITH_AWS_AUTH', s3_aws_auth.enabled().to_int())

src/libstore/package.nix

@@ -14,6 +14,7 @@
   libseccomp,
   nlohmann_json,
   sqlite,
+  cmake, # for resolving aws-crt-cpp dep
 
   busybox-sandbox-shell ? null,
 
@@ -25,7 +26,7 @@
 
   withAWS ?
     # Default is this way because there have been issues building this dependency
-    lib.meta.availableOn stdenv.hostPlatform aws-c-common,
+    (lib.meta.availableOn stdenv.hostPlatform aws-c-common),
 }:
 
 let
@@ -57,7 +58,8 @@ mkMesonLibrary (finalAttrs: {
     (fileset.fileFilter (file: file.hasExt "sql") ./.)
   ];
 
-  nativeBuildInputs = lib.optional embeddedSandboxShell unixtools.hexdump;
+  nativeBuildInputs =
+    lib.optional withAWS cmake ++ lib.optional embeddedSandboxShell unixtools.hexdump;
 
   buildInputs = [
     boost