Just because you didn't modify Foo.pm doesn't mean your version number doesn't need to change. Does your system handle that case?

If I were going to automate version numbering then I'd likely put the version number outside of Foo.pm (into a file just for the version number) and patch my "make dist" step to increment the version number in that file after the distribution is written.

I'm not tempted to automate this since doing it manually is such a tiny part of what it takes to make a release. I certainly won't be tieing some internal revision control number to the module version number, as that adds ugliness to the version number and adds an internal-to-external tie, something that often leads to complications.