On Wed, Oct 9, 2024 at 1:42 PM Alice Ryhl <aliceryhl@xxxxxxxxxx> wrote: > > Note that RUSTC_BOOTSTRAP is also defined in the top-level Makefile, but > its value is unfortunately *not* inherited from the environment. That I would perhaps say ", but Make-exported variables are not inherited" or similar to be a bit more precise (because the external environment, as in the `make` environment, is exported unlike those variables). > not look for the standard library. It's not possible to instead supply a > standard library to rustc, as we need `rustc-option` before the Rust > standard library is compiled. The error message mentions `std`, so to clarify I would perhaps add ".... standard library (i.e. `core`)" or similar, i.e. one could think `no_std` is enough otherwise (which would be better if we could, since it is stable unlike `no_core`, but we don't want it here either). > The -o and --out-dir parameters are altered to fix this warning: > > warning: ignoring --out-dir flag due to -o flag > > The --sysroot flag is provided as we would otherwise require it to be > present in KBUILD_RUSTFLAGS. The --emit=obj flag is used to write the > resulting rlib to /dev/null instead of writing it to a file in > $(TMPOUT). "the resulting object file" (i.e. the rlib is not written even if we wrote to a file). > I verified that the Kconfig version of rustc-option doesn't have the > same issues. Thanks for checking this. We may want to make it closer to what we do her, but that can be done later. Cheers, Miguel
