I’ve just pushed two GitHub actions:
a) Cachix action that allows you to run nix-build with the help of binary caches from Cachix. It’s such a simple way with a few lines of configuration to get a pretty decent Nix CI set up in a minute.
b) Install Nix action takes care of installing Nix as a step. This sounds like it should be simple, but there are quite a few caveats, so I’ve decided to abstract those away into a simple step. It’s part of Cachix’s action.
You can now instantly get access at https://github.com/features/actions, although it’s still in beta.