these 2 derivations will be built:
  /nix/store/6qa8fwkw5liwnl092qw58iy0nrvmlh9n-nixos-test-driver-pg_repack.drv
  /nix/store/96c4vhzrvbg4n65s0f9639ackvvvivyz-vm-test-run-pg_repack.drv