I don’t think we do anything special with Hugo’s cache - are you putting it there? Here’s our cache handling from the shell script that runs your build, and I see no mention of hugo:
Regardless, the answer to your question is that clear cache and deploy means that we start without a cache, so nothing would be there to start with.
Now, could hugo choose to stick something there? Yes, definitely, and I think we’d save it since I think we save that entire directory. But Hugo would have to work without the cache since it is not guaranteed available (and in fact won’t be e.g. on a new site, or on a new branch or PR on an existing site where we start with fresh cache).
Could you remove it after build? Also yes -
hugo && rm -rf $NETLIFY_CACHE_DIR/* would probably work.
Not sure why you were asking (as the main caching we intend to do with hugo’s output is at the CDN edge), but if that didn’t answer your question let me know some more about what you’re trying to accomplish