From fe39a233ea52601d416a1d02e7f70049aae47016 Mon Sep 17 00:00:00 2001 From: Antoni Boucher Date: Wed, 29 Jul 2026 19:38:03 +0200 Subject: [PATCH] rust: kbuild: disambiguate `zerocopy` for `rusttest` Starting with Rust 1.76.0, `zerocopy` was added as an (indirect) compiler dependency [1]. In turn, this meant that the `rustc-dev` component started including a precompiled `zerocopy` crate in the sysroot. This makes `rusttest` fail because the compiler finds several candidates: error[E0464]: multiple candidates for `rmeta` dependency `zerocopy` found --> rust/kernel/prelude.rs:64:9 | 64 | pub use zerocopy::{ | ^^^^^^^^ | = note: candidate #1: .../lib/rustlib/x86_64-unknown-linux-gnu/lib/libzerocopy-dfef4cb07ca752aa.rmeta = note: candidate #2: ./rust/test/libzerocopy.rlib We cannot use `--sysroot=/dev/null` for these, thus point to the dependency explicitly. Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Antoni Boucher Cc: stable@vger.kernel.org Fixes: 567621523ab7 ("rust: zerocopy: enable support in kbuild") Link: https://github.com/rust-lang/rust/pull/118546 [1] Link: https://patch.msgid.link/20260729173803.13459-1-ojeda@kernel.org [ Investigated when it started happening, reworded to add that and to follow our usual style and sent on behalf of Antoni, who found this during his work to support Rust for Linux with the GCC backend, i.e. with `rustc_codegen_gcc`. - Miguel ] Signed-off-by: Miguel Ojeda --- rust/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/rust/Makefile b/rust/Makefile index 627ed79dc6f5..fbe0accc51a3 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -350,7 +350,7 @@ rusttestlib-pin_init: $(src)/pin-init/src/lib.rs rusttestlib-macros \ rusttestlib-kernel: private rustc_target_flags = --extern ffi \ --extern build_error --extern macros --extern pin_init \ --extern bindings --extern uapi \ - --extern zerocopy --extern zerocopy_derive + --extern zerocopy=$(objtree)/$(obj)/test/libzerocopy.rlib --extern zerocopy_derive rusttestlib-kernel: $(src)/kernel/lib.rs rusttestlib-bindings rusttestlib-uapi \ rusttestlib-build_error rusttestlib-pin_init $(obj)/$(libmacros_name) \ $(obj)/bindings.o rusttestlib-zerocopy rusttestlib-zerocopy_derive FORCE