these 3 derivations will be built:
  /nix/store/z98hcgmz8582kfx7nmk0gy1fa8brsazw-source.drv
  /nix/store/33g5523xl6ggiyig3shbhnasjplg2ibf-collie-1.26.4.drv
  /nix/store/95j4jgj70y3q5sxprsaibacj71w6yzkw-check-collie.drv