Can't seem to install llvm-config

Hello, I want to install llvm-config. I have tried putting libllvm, or just llvm in my configuration.nix system packages, aswell as my home-manager packages. Other tools seem to install just fine. Everything else installs just fine, but it gives command not found when running llvm-config.

Interestingly enough, llvm-config is accessible if I do nix-shell -p llvm.