Re: [PATCH] rust: Suppress searching builtin sysroot

[Boqun Feng <boqun.feng@gmail.com>]

On Tue, Nov 28, 2023 at 01:14:41PM -0800, Boqun Feng wrote:
> [Cc Catalin as well]
> 
> On Tue, Oct 31, 2023 at 08:10:14PM +0000, Matthew Maurer wrote:
> > By default, if Rust is passed `--target=foo` rather than a target.json
> > file, it will infer a default sysroot if that component is installed. As
> > the proposed aarch64 support uses `aarch64-unknown-none` rather than a
> > target.json file, this is needed to prevent rustc from being confused
> > between the custom kernel sysroot and the pre-installed one.
> > 
> > Signed-off-by: Matthew Maurer <mmaurer@google.com>
> > ---
> > 
> > This patch is prompted by the issue I encountered at
> > https://lore.kernel.org/all/CAGSQo01pOixiPXkW867h4vPUaAjtKtHGKhkV-rpifJvKxAf4Ww@mail.gmail.com/
> > but should be generically more hermetic even if we don't end up landing
> > that patch.
> > 
> 
> I'm able to reproduce the issue you mentioned here after
> `rustup target add aarch64-unknown-none`, and your patch fixed that.
> 
> Tested-by: Boqun Feng <boqun.feng@gmail.com>
> 

Looks like I spoke too soon... we need another fix onto this:

diff --git a/rust/Makefile b/rust/Makefile
index eda32ff757b1..c573d8881686 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -178,6 +178,7 @@ quiet_cmd_rustdoc_test_kernel = RUSTDOC TK $<
                --extern build_error --extern macros \
                --extern bindings --extern uapi \
                --no-run --crate-name kernel -Zunstable-options \
+               --sysroot=/dev/null \
                --test-builder $(objtree)/scripts/rustdoc_test_builder \
                $< $(rustdoc_test_kernel_quiet); \
        $(objtree)/scripts/rustdoc_test_gen

, this is for kernel doc test as kunit test.

Needless to say, I also have tested with that and confirm it fixes the
issue.

Regards,
Boqun

> Regards,
> Boqun
> 
> >  rust/Makefile          | 1 +
> >  scripts/Makefile.build | 1 +
> >  2 files changed, 2 insertions(+)
> > 
> > diff --git a/rust/Makefile b/rust/Makefile
> > index a27f35f924ec..0403e88e19fd 100644
> > --- a/rust/Makefile
> > +++ b/rust/Makefile
> > @@ -400,6 +400,7 @@ quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L
> >  		--emit=metadata=$(dir $@)$(patsubst %.o,lib%.rmeta,$(notdir $@)) \
> >  		--crate-type rlib -L$(objtree)/$(obj) \
> >  		--crate-name $(patsubst %.o,%,$(notdir $@)) $< \
> > +		--sysroot=/dev/null \
> >  	$(if $(rustc_objcopy),;$(OBJCOPY) $(rustc_objcopy) $@)
> >  
> >  rust-analyzer:
> > diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> > index 82e3fb19fdaf..6e4ee513cc3c 100644
> > --- a/scripts/Makefile.build
> > +++ b/scripts/Makefile.build
> > @@ -275,6 +275,7 @@ rust_common_cmd = \
> >  	--extern alloc --extern kernel \
> >  	--crate-type rlib -L $(objtree)/rust/ \
> >  	--crate-name $(basename $(notdir $@)) \
> > +	--sysroot=/dev/null \
> >  	--out-dir $(dir $@) --emit=dep-info=$(depfile)
> >  
> >  # `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
> > -- 
> > 2.42.0.820.g83a721a137-goog
> >