Lint does not report unused license

[paddy-hack]

While documenting the allowed licenses for a project I just started on I added LICENSES/CC0-1.0.txt. However, the project still has no files that actually use this license. That notwithstanding, running reuse lint did not report it as unused and neither did the REUSE API service as illustrated below

{
  "badge": "https://api.reuse.software/badge/gitlab.com/numismate/numismate",
  "hash": "a045ae100eb4d6e0385d67ccedc80f7ff3f53b8a",
  "last_access": "2020-12-13T04:42:06.853529",
  "lint_code": 0,
  "lint_output": "# SUMMARY\n\n* Bad licenses:\n* Deprecated licenses:\n* Licenses without file extension:\n* Missing licenses:\n* Unused licenses:\n* Used licenses: AGPL-3.0-or-later, CC-BY-SA-4.0, CC0-1.0\n* Read errors: 0\n* Files with copyright information: 16 / 16\n* Files with license information: 16 / 16\n\nCongratulations! Your project is compliant with version 3.0 of the REUSE Specification :-)\n",
  "status": "compliant",
  "url": "gitlab.com/numismate/numismate"
}

I removed all references to CC0 from my code base, as in git grep CC0 does not report any hits, to see if that made a difference but it did not.

[mxmehl]

Confirmed, thanks for the report! This clearly is a bug, and a regression. I tested with v0.7.0, and it worked as expected, but from v0.8.0 onwards this shows the current, wrong behaviour.

We clearly have to fix this, and create a test that catches such issues in the future.

[carmenbianca]

This is an incredibly weird issue, because it should've been tested against. Created #313 as a note-to-self that this shouldn't happen again.

#312 fixes this. Thanks a lot for reporting.