Issue tracker for llvmPackages_20 / c++23

[mazunki]

Attempting to update to llvmPackages_20 fails with the following (trimmed) output:

...musl-20.1.4-dev/include/c++/v1/__vector/vector.h:790:65: error: invalid application of 'alignof' to an incomplete type 'fs::Dirent'
...musl-20.1.4-dev/include/c++/v1/__vector/vector.h:355:24: error: no matching function for call to '__add_alignment_assumption'
...musl-20.1.4-dev/include/c++/v1/__vector/vector.h:352:24: error: no matching function for call to '__add_alignment_assumption'
...musl-20.1.4-dev/include/c++/v1/__vector/vector.h:358:24: error: no matching function for call to '__add_alignment_assumption'
// repeated 12 times.

I'm not exactly sure what's causing this to appear with this bump, but it seems like it's source defined at https://github.com/llvm/llvm-project/blob/87f0227cb60147a26a1eeb4fb06e3b505e9c7261/libcxx/include/__vector/vector.h#L788-800.

Any ideas on what causes this or how to fix it? Could it be we need to turn on a flag somewhere?

[mazunki]

We stumble into this issue on llvmPackages_18 when attempting to update to c++23: llvm/llvm-project#89891.

I will attempt to build llvmPackages_19 and see if that helps.

Also related, but not really a priority (I think): llvm/llvm-project#64939

[mazunki]

We now have llvmPackages_19, but we still have some pending fixes for C++23. I am currently working patching some of these: mazunki/bump-cxx-23. This is still pending work.

[mazunki]

Thanks for the merge, @alfreb !