these 2 derivations will be built:
  /nix/store/adcwp8lawfams69gsrspipsm8k38hihd-gascity-1.5.0.drv
  /nix/store/p8kb7as9nh9iz314wkqqkb807vfyczvl-check-gascity.drv
this path will be fetched (8.4 KiB download, 73.8 KiB unpacked):
  /nix/store/qzw96vdyndz1czr5jpjn8blpj5f00rib-flock-0.4.0