these 2 derivations will be built:
  /nix/store/h6fzfk2xc9yl8ccmxvay2qlhk6iy08ji-calendar-cli-1.0.0.drv
  /nix/store/dc8n4hi59lnmvf1hlkxvwh33qxmvnyrn-pim-0.2.0.drv