these 3 derivations will be built:
  /nix/store/qaydlx4w90a9p3q7c45jplrvqid92hm8-source.drv
  /nix/store/798mxmk0grdd7cpk6ms684ldvqkmi9aq-collie-1.15.2.drv
  /nix/store/l06ssls7f0j4wdcwfbqwb93bk394ks7z-check-collie.drv