these 2 derivations will be built:
  /nix/store/lcfjwl65kzv312v4kq0wlydv0my6y4z3-nixos-test-driver-pg_repack.drv
  /nix/store/kak5biwvm19klrgcppsdwavfmid7rbr0-vm-test-run-pg_repack.drv