Re: [OE-core] [PATCH V3 1/2] rust: Use clang instead of rust-llvm

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Fri, 2025-10-10 at 14:57 +0530, Deepesh Varatharajan wrote:
> 
> As you suggested, I was able to resolve the missing library issue by 
> creating symlinks from the native sysroot to the target sysroot.
> However, I'm now encountering a linker error during the build:
> 
> ../poky/build/tmp/work/cortexa15t2hf-neon-poky-linux-gnueabi/rust/1.90.0/recipe-sysroot-native/usr/bin/arm-poky-linux-gnueabi/../../libexec/arm-poky-linux-gnueabi/gcc/arm-poky-linux-gnueabi/15.2.0/ld: 
> ../poky/build/tmp/work/cortexa15t2hf-neon-poky-linux-gnueabi/rust/1.90.0/sources/rustc-1.90.0-src/build/x86_64-unknown-linux-gnu/stage1-rustc/armv7-poky-linux-gnueabihf/release/deps/librustc_llvm-3e591ab97f1ae683.rlib: 
> 
> error adding symbols: file format not recognized
> >            collect2: error: ld returned 1 exit status
> 
> Upon investigation, I found that the issue stems from architecture 
> mismatches within "librustc_llvm-3e591ab97f1ae683.rlib". I extracted
> the object files from this archive and ran the file command to inspect 
> them. Most object files were correctly built for the ARM 32-bit (target):
> ELF 32-bit LSB relocatable, ARM, EABI5 version 1 (SYSV), with 
> debug_info, not stripped
> 
> However, some of the object files (originating from the symlinked native 
> sysroot libraries) were built for the host architecture (x86_64):
> ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped
> 
> This mixture of architectures in a single .rlib is causing the linker to 
> fail, and confirms that symlinking missing libraries
> from the native sysroot won't work. So to resolve the issue we've left 
> with only one option to build llvm target also for all
> the architectures as we build for native llvm build.
> 
> Please let me know if you’re okay with this approach, and I can proceed 
> with sending the patch.

Thanks for trying that, I think it was worth trying and it is shame it
didn't quite work out. I agree with proceeding with the other
direction, thanks.

Cheers,

Richard