these 3 derivations will be built:
  /nix/store/l0jzvmgyhs6gy2frjq1p6yy762w6aw8m-source.drv
  /nix/store/jfj8g4hmfrz5njhnkg4m7wr29pn822d5-collie-1.27.0.drv
  /nix/store/x8jkwa6iaqk1vk6z1h7wijlnpw9qyjzv-check-collie.drv