these 2 derivations will be built:
  /nix/store/2hzji16wz6kzc3d2avn9a0wfcy6krqdg-calendar-cli-1.0.0.drv
  /nix/store/ziknz56bdi5s0y77vbnk93n6gw79cr9m-pim-0.2.0.drv