Unfortunately I don't know how I got into this situation, but today I got egg into a state where it stopped working, because of an extra CR (^M) in one of the .git/rebase-merge/* files. Egg failed to parse the branch name "topic/foo^M" (where ^M was a real CR in the actual file) as a rev.
I wonder if egg-file-as-string should strip CRs, at least on Windows?