these 3 derivations will be built:
  /nix/store/irgbimn37apgfw0cqb878xvq1kk933km-source.drv
  /nix/store/rmzds8zhvpg0y971vvwm5j8wfm4dfnwl-collie-1.21.3.drv
  /nix/store/kgs75kn5lshyhlpcn0sb1ib20cw1s5m6-check-collie.drv