libcxx 15.0.0.rc's

[h-vetinari]

No description provided.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[h-vetinari]

Sounds like this is running into llvm/llvm-project@21f73d5

[h-vetinari]

@isuruf
I fear the old build scripts might be reaching the end of their applicability. Upstream has now completely removed the ability to do standalone builds:

Support for standalone builds have been entirely removed from libc++, libc++abi and libunwind.

I don't know why we need(ed) to build libcxxabi separately, so while I'm able to move to the new build instructions, I don't know what aspects we need to achieve for continuity.

[h-vetinari]

Ping @isuruf; can we move to a single build for libcxx+libcxxabi here?

[h-vetinari]

Ping @isuruf; rc3 was just released and if possible I'd like to try building the whole stack before GA.

[isuruf]

Can you move this to a single build? We can assess after that is done if it does the same thing we had before.