Comment # 3 on bug 1090853 from Michal Srb

(In reply to Ismail Donmez from comment #1)
> Only the latest stable llvm version should provide libc++ & libc++abi
> packages. Since it's always ABI compatible old clang can use them as well.

That makes sense.

(In reply to Ludwig Nussel from comment #2)
> so maybe a model similar to gcc is needed where the prjconf defines the
> default version

We have a meta package "llvm" that depends on the default version. But if we
have to conditionally disable the build of some subpackages, then I guess a
prjconf define would be the way to get it?