I want to check my projects against upcoming LLVM 21, the library. I see that there is some Nix code for LLVM 21 Release Candidate in Nixpkgs/git-master, but I have no idea how to make use of that. I know I can access a certain LLVM version via llvmPackages_20.libllvm, but there is no llvmPackages_21.libllvm. But I guess, it is equally simple. Can someone give me a hint?
In the git-log of nixpkgs I found llvmPackages_git. This is not quite the release candidate, but I think it solves my problem at hand.