Why do we need to include hash in the cache key?

[justin-pierce]

I noticed that my hash would change when I made changes, invalidating the cache and making this action only useful when re-running the same workflow ref. Perhaps because I'm copying files into the image. In my local and deployment environments, most of the cache is still functional -- with this action, it'd invalidate the entire cache.

So I tried setting the cache key manually without the hash and in my limited testing, it seems to work as I'd expect it to (the steps before the copy still use cache). Wondering if I'm missing anything that might come back to bite me. Thanks

edit: further testing suggests this isn't working after all. Is this Action supposed to work when triggered by pull requests?