If /a/b and /a/b/c are both in the watch list, we should reduce that internally to just /a/b

[passcod]

That was always a thing but never an issue until 8.2.0 where suddenly a lot of dependencies can appear in the watch list, plus the root. If we're watching the root anyway, we should just skip all paths that are within it. In a more general fashion, see the title.