these 2 derivations will be built:
  /nix/store/vidi5c37rys0ybm0xqgbp9cbak3qi66x-nixos-test-driver-pg_repack.drv
  /nix/store/8cmr1g8gsd7k81zdkmqmypj2n8yrzllg-vm-test-run-pg_repack.drv