Created attachment 750327 [details]
Proposal for a fix using a new virtual/libunwind ebuild
When compiling with LLVM / clang version 12, we can now use the sys-libs/llvm-libunwind package as default unwinder.
Some package currently using sys-libs/libunwind can benefit of the llvm unwinder when compiled using clang.
In order to simplify the changes for those packages, here's a new virtual/libunwind proposal.
This is related to net-fs/samba issue ID #791349
Note that some packages do need libunwind and don't work with llvm-libunwind (or at least, dev-lang/julia does last I know of -- unsure if there's more).
There's also the need to handle automatic rebuilds (subslot change, or to change the provider).
Not that *unwind is something I really looked into, just to say it's not that simple.
I have to admit I'm not aware of libunwind internal subtilities, then I won't claim this patch is to be applied to all packages using this feature.
But I still think this virtual can be an helper for some selected packages in order to build them using clang.