i think my favourite answer to “how do you make sense of git merge histories" so far is “use git log --merges"
this seems pretty good, but it's hard to get a nice one-line summary of each merge with --oneline because the first line of the merge is just something like "Merge pull request #148 from briankassouf/race-detector” (instead of “Add a -race flag to enable Go's race detector on builds" which would be a more useful summary)
alcinnz