Running Tests
You can run tests using nix-build. For example,
to run the test
login.nix,
you do:
$ cd /my/git/clone/of/nixpkgs
$ nix-build -A nixosTests.login
After building/downloading all required dependencies, this will
perform a build that starts a QEMU/KVM virtual machine containing a
NixOS system. The virtual machine mounts the Nix store of the host;
this makes VM creation very fast, as no disk image needs to be
created. Afterwards, you can view a log of the test:
$ nix-store --read-log result