Undefined temporary symbol `$BB342_17` when compiling `rustc-demangle`

[AaronKutch]

Checklist

• [X] I've looked through the issues and pull requests for similar reports

Describe your issue

When I run cross test --target mips-unknown-linux-gnu -Z build-std=core,alloc,proc_macro,std --features=std,zeroize_support,rand_support,serde_support,dag,try_support,debug on awint v0.12.0 (https://github.com/AaronKutch/awint/commit/74f41a5f41707e4c87dda98d51691c753465647a ) and cargo 1.74.0-nightly (925280f02 2023-08-25)

What target(s) are you cross-compiling for?

mips-unknown-linux-gnu

Which operating system is the host (e.g computer cross is on) running?

• [ ] macOS
• [ ] Windows
• [X] Linux / BSD
• [ ] other OS (specify in description)

What architecture is the host?

• [X] x86_64 / AMD64
• [ ] arm32
• [ ] arm64 (including Mac M1)

What container engine is cross using?

• [X] docker
• [ ] podman
• [ ] other container engine (specify in description)

cross version

cross 2.5.0

Example

navigate to workspace root and run cross test --target mips-unknown-linux-gnu -Z build-std=core,alloc,proc_macro,std --features=std,zeroize_support,rand_support,serde_support,dag,try_support,debug I get the result

error: Undefined temporary symbol $BB342_17

error: could not compile `rustc-demangle` (lib) due to previous error

Additional information / notes

No response

[AaronKutch]

I know that mips was demoted recently, this isn't necessary if I could run s390x-unknown-linux-gnu (I need a 32-bit big endian system) which seems to be blocked by the libtest issues

[taiki-e]

This is rustc/llvm bug, and can be worked around by enabling optimization. https://github.com/rust-lang/rust/issues/108835#issuecomment-1636983993

[urosbericsyrmia]

This issue should be fixed by llvm/llvm-project#80799. Initially, the cause of the issue and the solution are explained in llvm/llvm-project#80666, but more elegant solution is just to remove derived isBlockOnlyReachableByFallthrough for Mips architecture.