these 2 derivations will be built:
  /nix/store/zzm0vzhjcs1y2f901z9jkkmg3cpq2xgy-nixos-test-driver-pg_repack.drv
  /nix/store/8dp3mf4zp21931600d1ayprlgfan5yv2-vm-test-run-pg_repack.drv