these 2 derivations will be built:
  /nix/store/qv6p1rvh1yh3fg9d172kx815nl5vsn7q-nixos-test-driver-pg_repack.drv
  /nix/store/x9dzyqqhg0x5h6g3p900rsbxmwp541fl-vm-test-run-pg_repack.drv