Linker error with LLVM 18.1.8: std::exception_ptr::__from_native_exception_pointer(void*) about homebrew-core HOT 6 CLOSED

Previous versions of homebrew LLVM worked fine out of the box

Just noting that similar issues could have (and did) happen with previous LLVM versions depending on how old the version of Xcode's LLVM was. The root cause is mixing of different LLVM headers and libraries is not officially supported.

LLVM 18 specifically introduced changes to std::make_exception_ptr so any code that uses it hits the failure when linking to Xcode's libc++.

A prior situation was LLVM 15/16 introducing verbose abort feature (which impacted Monterey and older), e.g. llvm/llvm-project#87590

from homebrew-core.

Can you try adding

-L"$(brew --prefix llvm)/lib/c++" -L"$(brew --prefix llvm)/lib" -lunwind

to cxxflags when building to see if it helps?

from homebrew-core.

Can you try adding

-L"$(brew --prefix llvm)/lib/c++" -L"$(brew --prefix llvm)/lib" -lunwind

to cxxflags when building to see if it helps?

With those flags added to linkflags the libraries successfully build. Full command is now:

./b2 cxxstd=20 toolset=clang --stage linkflags="-L"$(brew --prefix llvm)/lib/c++" -L"$(brew --prefix llvm)/lib" -lunwind"

from homebrew-core.

Good to know, thanks. Do you consider this issue resolved?

The solution isn't ideal, but making it better could prove a little painful for some other users...

from homebrew-core.

Good to know, thanks. Do you consider this issue resolved?

The solution isn't ideal, but making it better could prove a little painful for some other users...

Do you expect this to be a temporary or permanent workaround? Previous versions of homebrew LLVM worked fine out of the box and there's now a few other issues elsewhere pointing to this one.

from homebrew-core.

Yes, the issue seems to be that LLVM prioritises use of its included C++ headers when it has no guarantee that it will be linking with a compatible libc++. For a long time this didn't cause anyone problems. I'm not sure if this was by chance, or if there's been a policy change upstream.

from homebrew-core.