these 4 derivations will be built:
  /nix/store/jjlbnckx92dr1brfa58ds4pmwncpv66p-source.drv
  /nix/store/p880ygbqimwsm0jcfny5fk8dysihvq24-mercat-0.3.8-zig-deps.drv
  /nix/store/hj78srrgcm7kjgyw16svajmi0aladxgw-mercat-0.3.8.drv
  /nix/store/6gjjk351jm7ncwvcwb1rfgw1d5a9s7wv-check-mercat.drv