Quibble supports a --change argument that allows users to supply a change ID. This is helpful for testing patches locally (environments where git://contint1002.wikimedia.org is not available).
The implementation in util.py supports fetching patchsets (e.g. FetchInfo.change(12345, 42)), but the code that calls it (cmd.py#L197) only ever calls FetchInfo.change with a single argument. This fails with an HTTP 400 error in the case that the --change argument is, for example, 12345,42.
Enhance the current implementation in cmd.py so that patchset arguments can be processed.
When this support is added, the corresponding code in jenkins-run-analysis can be updated to also process / handle patchsets.