What advantage do long commit messages have? In most open source projects, commit messages are very short. however, it is extremely easy to follow the progress through history as the code changes are always kept less comprehensive. but I would like to listen to the advantages of writing long commits.
I can't speak about it in the context of open source projects, but here are some general benefits:
* Easier for your reviewers to understand the context of the change => easier to review the code (I think this alone makes it worth it)
* Keeps you accountable to yourself. By clearly describing the problem and the solution, it gives you an opportunity to spot when you're solving the wrong problem, not solving the whole problem, or solving it the wrong way, or including unrelated changes in your commit.
* Provides historical context. Sometimes over time the purpose of a particular part of the code becomes less clear, but with git blame you can immediately see it, assuming the commit message describes it well enough. (Yes, ideally the code will speak for itself or be supported by comments, but we don't live in an ideal world - and the comments may not be in the part of the code you are reading)
* Teaching opportunity - e.g. "we use approach A because the more obvious approach B has problem X" (again, sometimes better captured in comments, but not always)
