these 2 derivations will be built:
  /nix/store/bb12psmigs3hwfaklxhh49sisn8h93dk-nixos-test-driver-pg_jsonschema.drv
  /nix/store/a91l1027qmf45s8rv060ngz7h9drjbi6-vm-test-run-pg_jsonschema.drv