in reply to Semantic diff for Perl code
The solution that comes to mind is to do a git diff on the github repository that houses the module's source code. This assumes that the module's code is stored on github, and that the revision numbers are tagged in the repository.
Failing that, you may have to download and unpack the versions you want to compare in order to do a recursive diff on the two trees.
In Section Seekers of Perl Wisdom