in order to work around the limitations of not having github actions' marketplace, this approach opts to use nixpkgs as a source for packages. alternate registries can be specified too, these are expected to be nix flakes that expose packages. this takes a page out of replit's approach to supplying packages to their devshells, however, instead of using nix syntax, we use only a flake + package combo, and the compiler will simply convert this into a step like so: nix profile install flake#package Signed-off-by: oppiliappan <me@oppi.li>