I think the Go guideline to commit messages is exceptionally good: https://golang.org/doc/contribute.html#commit_messages.
Also: Rob Pike's Google internal rant on the very same topic https://groups.google.com/forum/#!topic/golang-dev/6M4dmZWpF...
2 karma · joined June 12, 2018
Also: Rob Pike's Google internal rant on the very same topic https://groups.google.com/forum/#!topic/golang-dev/6M4dmZWpF...