these 2 derivations will be built:
  /nix/store/2lasg9wqimz3n6q7bqgk7w0zsz72377b-flake-fmt-1.0.0.drv
  /nix/store/vqv34cmp5k16w37fxhyd7wsbxvcnqr85-merge-when-green-0.3.0.drv