these 2 derivations will be built:
  /nix/store/5zjx699jj9z14j93pm9yik5rwyhr7337-nixos-test-driver-pg_repack.drv
  /nix/store/xjxhzkj4fh7g0a2mqsy87nkw3l2hyn9p-vm-test-run-pg_repack.drv