these 2 derivations will be built:
  /nix/store/qg6ljnqi6na7bkvw9gr9hbzvafnl5igj-nixos-test-driver-pg_repack.drv
  /nix/store/wyxw4bfwf6ld9yw19an1ccj7x3139c0a-vm-test-run-pg_repack.drv