these 2 derivations will be built:
  /nix/store/1sj26m9r7shpy99z7z539fqmajr39jbd-nixos-test-driver-pg_repack.drv
  /nix/store/2dzk8xcsss19g0ab15ryvri01ayigy9d-vm-test-run-pg_repack.drv