It's possible to run the test suite using `stack test` or `stack build` with the right arguments. This works alright and is relatively fast if you have a `.stack-work` with all the dependencies cached. If you don't then it's a long wait to build everything. iohk haskell.nix supports building/running tests too. It does about the same thing as `stack test` but uses the Nix build cache. The Nix cache is a bit better than the `.stack-work` cache because it is more fine-grained and less apt to get accidentally wiped. It would be great to have both these options to increase the chances of having a usable cache around.