these 3 derivations will be built:
  /nix/store/sdj09ibrr08prryxphyqxi5qwhs2idis-source.drv
  /nix/store/mfylch64f8ag6wg419973vsbp7v2i3y2-fx-0.0.12.drv
  /nix/store/m3bgnpig0qbhbhqn8fjp2i8ws96066p8-check-fx.drv