these 3 derivations will be built:
  /nix/store/6j1gin04xpx2zw5nffamp6bxh0w03f1s-source.drv
  /nix/store/cb0yyrvrm1hwgkmrpmv12fm3zj2fax3d-collie-1.25.5.drv
  /nix/store/m8p5swhavpxps74wgi33lpr13znkrqg2-check-collie.drv