these 4 derivations will be built:
  /nix/store/nx5v7s8sbqaysiy9v6p92sfzbk2g8mik-hm-firefox-extensions.drv
  /nix/store/yhpnxgsm1nkxfdjlqfz8c210pndj11ns-hm-firefox-extensions.drv
  /nix/store/5bv6mbyjj04z4hyy9jcxfrzdxza28kj1-home-manager-files.drv
  /nix/store/ghbxpijq4fj7yp8pa7ly6838gmjdkwdz-home-manager-generation.drv