these 4 derivations will be built:
  /nix/store/3y2vgm7rn42z9njpjb3385na5nv844nx-hm-firefox-extensions.drv
  /nix/store/9ygzi15hwbs8vcrb37dmh4l5j3yak5x4-hm-firefox-extensions.drv
  /nix/store/6wqjkllc28a45vkhiamrmzcj290fmgmd-home-manager-files.drv
  /nix/store/s63ybdfpdbrdz0bv5sy4inzxzfqvc96c-home-manager-generation.drv