these 3 derivations will be built:
  /nix/store/nj8f2lxzydwssvixnd52j1x19qzjklqc-source.drv
  /nix/store/6hsklcspjamjkdzw9p6w790yc0qz4jyh-collie-1.15.2.drv
  /nix/store/l8kq91xjdnbb4kgwdi524mpp6ysm4giz-check-collie.drv