these 3 derivations will be built:
  /nix/store/b3ph5ccz3d7an32k1pv07h7lsjmnwvfk-cpa-usage-keeper-frontend-1.15.10.drv
  /nix/store/66y483fsrfii69h0as7clsrl92dcpgac-cpa-usage-keeper-1.15.10.drv
  /nix/store/8c1nh567l81dccqgsksj0xihd3x5zr6x-check-cpa-usage-keeper.drv