[heads]

To tack one additional problem onto your excellent list: the commit message is usually only the start of a conversation about why a change should be made. The rest of that discussion is whether it meets the bar and what needs to be adjusted before it can land on the collaborative trunk. Done well, that is valuable reading.

Git was designed with the distributed viewpoint. A commit message, as written by the author, is necessarily correct: I’ve decided this is right, and it’s on you to decide if you want to merge it into your history too.

In our current systems we usually have a URL in the commit message that links to the actual story behind the commit — the discussion on the pull request, merge request, or code review. I rarely see the results of these discussions being amended into the commit message. If the repo lives forever but the database behind the code review tool gets toasted then something just as important is lost forever.

(I come from a background of one idea equals one amended, fast forwarded commit to master. It’s possible other people rely on branch history to reflect the evolution of ideas and how they go from a request for review to approved code. In my experience branch histories tend to have very low quality commit messages and even then they only show one side of the conversation — the author’s responses to their reviewer’s and their own critiques.)