buildRustCrate calls rustc directly, so there is no built-in equivalent
of `cargo clippy`. The capLints doc already hints at the existing
workaround — overriding the `rust` attribute with a wrapper script that
sniffs argv for build_script_build and routes everything else to
clippy-driver. That works because clippy-driver IS rustc internally
(rustc_driver plus lint passes) and produces compatible rlibs and
metadata, but the wrapper is fragile and every downstream reinvents it.
Add a `useClippy` boolean (default false) that swaps the lib/bin/test
compilation to clippy-driver while keeping plain rustc for build.rs —
the same lib-vs-build-script split as extraRustcOptsForBuildRs, since
build scripts are typically auto-generated and clippy noise there is
not actionable. The clippy-driver binary comes from a new `clippy`
parameter, auto-filled from pkgs.clippy by callPackage and overridable
alongside `rust` for toolchain bundles that ship their own.
Implemented by introducing a RUSTC_DRIVER shell variable in
build-crate.nix that lib.sh's build_lib/build_bin consume; the
build_script_build path in configure-crate.nix never sees it.
Note that the default `capLints = "allow"` cap suppresses clippy lints
along with everything else, so `useClippy` is usually paired with
`capLints = "warn"` and `-W clippy::*`/`-D warnings` flags via
extraRustcOpts. Documented in the manual.
Test fixtures cover the three load-bearing properties: a denied clippy
lint fails the build (proving clippy-driver ran), the default capLints
silences clippy lints just like rustc lints, and an rlib emitted by
clippy-driver is link-compatible with a plain-rustc dependent.
Proc-macro crates are host dylibs that rustc dlopen()s. Instrumentation
flags passed via extraRustcOpts (e.g. -Zsanitizer=address,
-Cinstrument-coverage) leave unresolved runtime symbols in those dylibs
and break the build. Cargo avoids this by not applying RUSTFLAGS to host
artifacts; buildRustCrate already has extraRustcOptsForBuildRs for build
scripts, so add the analogous knob for proc-macros.
Defaults to null, which falls back to extraRustcOpts so existing callers
are unchanged. Set to [] to opt proc-macros out when applying
sanitizer/coverage flags tree-wide via crateOverrides.
Cargo's `[lints]` table is a cargo-only feature: cargo translates the
entries into `-A`/`-W`/`-D`/`-F` rustc flags before invoking the
compiler. Since buildRustCrate calls rustc directly, these lints were
silently ignored, forcing users to duplicate them as raw flags in
`extraRustcOpts`.
Accept a `lints` attr with the same shape as the Cargo.toml section
(tool → lint name → level string or `{ level, priority }` attrset),
translate it to rustc flags in Nix, and append to the rustc command
line. Entries are sorted by ascending priority so lower-priority lint
groups are emitted first and can be overridden by more specific lints,
matching cargo's behaviour.
The `capLints` default changes from `"allow"` to `null`, resolved to
`"allow"` when `lints` is empty (the usual case for third-party
dependencies) and `"forbid"` when `lints` is set — otherwise a
`deny`/`forbid` lint would be silently capped and the table would be a
no-op. Explicit `capLints` still overrides. This is the same model
cargo uses: your own crate's `[lints]` always apply; only
dependencies get `--cap-lints allow`.
Generators like crate2nix can populate `lints` directly from the
manifest at generation time.
lib.sh previously hardcoded `--cap-lints allow` in both build_lib and
build_bin. Since rustc only honours the first `--cap-lints` it sees,
appending a different level via `extraRustcOpts` had no effect, making
it impossible to run clippy (or any lint-based tooling) through
buildRustCrate without wrapper scripts that strip the argument.
This adds a `capLints` parameter (default `"allow"`, preserving current
behaviour) that can be set per-crate or via `.override`:
(myCrate { }).override { capLints = "warn"; }
Cargo uses the basename of a JSON target specification in various places
to refer to targets, cc-rs parses the basename to grab target
information. There may be other examples where the basename is relevant.
Instead of fighting these existing conventions, let's just recommend
users provide a rustcTargetSpec, either as a standard name or as a
custom JSON file with the right basename
This reverts commit 65a333600d.
This wasn't tested for correctness with something like fodwatch [0],
and should not have been (self-)merged so quickly, especially without
further review.
It also resulted in the breakage of at least one package [1] (and that's
the one we know of and was caught).
A few packages that were updated in between this commit and this revert
were not reverted back to using `rev`, but other than that, this is a
1:1 revert.
[0]: https://codeberg.org/raphaelr/fodwatch
[1]: https://github.com/NixOS/nixpkgs/pull/396904 / 758551e458
Cargo 1.84.0 broke fetchCargoTarball hashes, so fetchCargoTarball is
not long for this world. Tell people to use fetchCargoVendor, which
Nixpkgs is currently in the process of switching to across the tree.
every other format is deprecated, so to imply that people should be setting it is misleading
(`pyproject = true` should also go away eventually, but is the way until
then)
so that meta.description examples shown in the documentation
align with recommendations given in the "Meta attributes" section
in pkgs/README.md.
The changes were made with the following commands:
nix run nixpkgs#silver-searcher -- -l0 'description\s*=\s*"([Aa]n?|[Tt]he)\s' doc \
| xargs -0 nix run nixpkgs#gnused -- -i '' -Ee '/description/s/"([Aa]n?|[Tt]he)\s(.)/"\U\2/'
nix run nixpkgs#silver-searcher -- -l0 'description\s*=\s*".*\."' doc \
| xargs -0 nix run nixpkgs#gnused -- -i '' -Ee '/description/s/\."/"/'
`rustc.config` is called `rust.rustcTarget` now, and
`{rustc -> rust}.platform`.
This is the new way (tm), and is preferred since
https://github.com/NixOS/nixpkgs/pull/271707 -
though the documentation still is outdated, and some expressions in
nixpkgs were using the old interface.
This updates both.
Following [Best Practices](https://nix.dev/guides/best-practices#with-scopes),
`with` is a problematic language construction and should be avoided.
Usually it is employed like a "factorization": `[ X.A X.B X.C X.D ]` is written
`with X; [ A B C D ]`.
However, as shown in the link above, the syntatical rules of `with` are not so
intuitive, and this "distributive rule" is very selective, in the sense that
`with X; [ A B C D ]` is not equivalent to `[ X.A X.B X.C X.D ]`.
However, this factorization is still useful to "squeeze" some code, especially
in lists like `meta.maintainers`.
On the other hand, it becomes less justifiable in bigger scopes. This is
especially true in cases like `with lib;` in the top of expression and in sets
like `meta = with lib; { . . . }`.
That being said, this patch removes most of example code in the current
documentation.
The exceptions are, for now
- doc/functions/generators.section.md
- doc/languages-frameworks/coq.section.md
because, well, they are way more complicated, and I couldn't parse them
mentally - yet another reason why `with` should be avoided!
Fixes some mistakes regarding the references to cargoHash in the codes referenced.
Fixes a typo for cargoSha256.
States that cargoHash should be preferred.
We keep running into situations where we can't get the right
combination of rustc flags through build systems into rustc.
RUSTFLAGS is the only variable supported across build systems, but if
RUSTFLAGS is set, Cargo will ignore all other ways of specifying rustc
flags, including the target-specific ones, which we need to make
dynamic musl builds work. (This is why pkgsCross.musl64.crosvm is
currently broken — it works if you unset separateDebugInfo, which
causes RUSTFLAGS not to be set.)
So, we need to do the same thing we do for C and C++ compilers, and
add a compiler wrapper so we can inject the flags we need, regardless
of the build system.
Currently the wrapper only supports a single mechanism for injecting
flags — the NIX_RUSTFLAGS environment variable. As time goes on,
we'll probably want to add additional features, like target-specific
environment variables.
