@terriko what do you think?

This looks promising!

I've approved the tests to run, but they'll likely fail because we've got a broken cache in our CI system at the moment. While we're working on getting that fixed, some thoughts:

• We should have a test to make sure this works
• You're going to want to update the documentation where we mention the cache (I think we do in a few places)
• I'm not sure this is going to handle the case where XDG_CACHE_HOME isn't set, so we might need to have it do a default there
• We may need to be careful about how it works on Windows (path stuff is always tricky there)

@terriko I rebased my branch on main and added tests for database_defaults.py which include testing the cache directory behaviour. When XDG_CACHE_HOME is not set then the default path is used ~/.cache. I also updated the MANUAL.md with Cache Directory Behavior section where it is clearly (I hope so!) explained.

Thanks! I'll get the tests running again. Our cache issue is resolved so if they don't all pass this time, do take a look to see if you need to fix something.

@terriko I forgot to run linters locally on a test file - my bad. I also fixed the tests so they will work on Windows properly. I noticed that:

• spell checking job complains about XDG word
• test_source_osv.py::TestSourceOSV::test_update_ecosystems() failed and it looks like expected_ecosystems downloaded from https://osv-vulnerabilities.storage.googleapis.com/ecosystems.txt are not the same as self.osv.ecosystems

Shall I do anything about these?