GitHub, GitHub actions, Nix, Cachix, Cabal & Stack are all free.
This is using the scarf commercial cachix cache for push/pull between builds currently (which is fine.) But this could easily be changed to something else. I can provide you the scarf cachix publish key for an environment variable. Or you could go to Cachix and use a free account. Create a Read/Write token and add it to the project as an environment variable.
Problem:
Travis CI is no longer free.
Solution:
GitHub, GitHub actions, Nix, Cachix, Cabal & Stack are all free.
This is using the scarf commercial cachix cache for push/pull between builds currently (which is fine.) But this could easily be changed to something else. I can provide you the scarf cachix publish key for an environment variable. Or you could go to Cachix and use a free account. Create a Read/Write token and add it to the project as an environment variable.