these 2 derivations will be built:
  /nix/store/04gb4r36w3gb8jfzj1vxi6h6z4xw19b1-nixos-test-driver-pg_repack.drv
  /nix/store/6mwwcw384y841k1la4j634wr9yad1wlv-vm-test-run-pg_repack.drv