Failure notes:

• Apple and thumb (via rust-lld) do not seem to support the flag
• powerpc- has errors frombss-plt forced due to ....
• wasm gets a lot ofis neither Wasm object file nor LLVM bitcode warnings. These seem to be all the object files from the C code we build, e.g.absvdi2. I am not sure why we build the C versions in the first place, since the readme says they are never called by LLVM. There is some context to whyfatal-warnings isn't passed on wasm, not directly relatedRemove --fatal-warnings on wasm targets rust#120278.
• windows-gnu has corrupt.drectve warnings. Looks like this is a known issueGNU linker warns “corrupt .drectve” on staticlib binary generated with Rust 1.70 on Windows rust#112368

For MSVC it's/WX

Does it ignore unrecognized link args?fatal-warnings is still getting passed and it doesn't seem to complainhttps://github.com/rust-lang/compiler-builtins/actions/runs/10343839608/job/28628523945?pr=667#step:11:23

I mean.../Wx isn't being passed yet?

> rustc hello.rs -C link-args='/WX --fatal-warnings'error: linking with `link.exe` failed: exit code: 4044[...]  = note: LINK : warning LNK4044: unrecognized option '/-fatal-warnings'; ignored          LINK : error LNK1218: warning treated as error; no output file generated

Oh, unrecognized linker args are warnings by default rather than errors? I was just expecting it to complain like the other targets that don't support-Wl,--fatal-warnings do.

The wasm issue isrust-lang/rust#132802, I still haven't updated the Windows flags.