I had a snap/hooks/prepare-slot-serial-port hook script and built the snap. I then realized I did not want the hook, so I deleted the file and re-ran snapcraft. The final snap still contained the hook script, so I had to clean and build, which took a long time since this is building a a gadget on pi3. Expected behavior: snapcraft would detect a previous hook script is no longer present and create a new snap without it, without needed to clean first.