The version control in Squeak, based on Smalltalk-80, has been in use for over 16 years, probably even 32 years. The community of Squeak has been entirely happy

The version control in Squeak, based on Smalltalk-80, has been in use for over 16 years, probably even 32 years. The community of Squeak has been entirely happy with it, it could perhaps be made even more convenient with more diff analysis tools. For every snippet, even a single line in a method, all the versions are kept around and the blame for the revisions to a previous version, including deletions, is always clear. The last version is active (there is no compiling fase in smalltalk, only auto compile for adaptive compilation). So your question is never relevant unless one wants to merge back after a fork. In that case diff tools should give a human the entire history, diffs and all its dependancies that are affected to see what happend when and how. It is indeed useful to see changes going back 40 years. In the case auto-merge-back is possible, the S unit test runner must check if it worked, but such a situation occurs only once in 10 years if at all. So to me there is not much to be desired in a version control system than the current method version control of Squeak.