these 2 derivations will be built:
  /nix/store/x6vzk4wwkvji7804b059n0szmzpywf6x-nixos-test-driver-pg_graphql.drv
  /nix/store/0q2yjlbl9mq6zd2zasgwvqwk7sicy5m7-vm-test-run-pg_graphql.drv