these 3 derivations will be built:
  /nix/store/xcpr0fgvnwz9fmv974kyij7m52jad952-source.drv
  /nix/store/dhys6vam7214zsilpnsmagslymnb62f4-mcptoon-0.8.35.drv
  /nix/store/gwnv92y4ydb2s50qapwpbgxk9igvz1sg-check-mcptoon.drv