these 3 derivations will be built:
  /nix/store/k3f08lg5wh23m400cq423laxf2685x4n-source.drv
  /nix/store/dxp17fhfcjap4a2vh7h8z1spc4cs82vk-harmonia-deps-3.1.0.drv
  /nix/store/hf1a8jrf6pln62ndlixprlcfsr6pm1g5-harmonia-3.1.0.drv