these 2 derivations will be built:
  /nix/store/s0yvm2b98ysmwfk3w0hsimgm1gwyj62q-nixos-test-driver-pg_repack.drv
  /nix/store/yr26yzgklb85p44z21zqwfi1dhwfxk5n-vm-test-run-pg_repack.drv