We’ve previously had some issues with PyGit2 (which we use for parsing Git diffs) loading diffs (due to bugs in PyGit2) that have either empty files or file renames.

Some patch builds for WT-13397 are failing, and this appears to be due to PyGit2 being unable to load the diff for the changes. These patches appear to have found another edge case.

Here is an example of an error message from PyGit2:

_pygit2.GitError: invalid patch header at line 31