I have a custom merge driver that works well. However I can only run it when performing merges locally on my machine. It would be really nice if it was run when Github merges.
Obviously Github will not want to run executable files provided by their users. However perhaps it would be possible to specify a websocket endpoint to which the three versions are sent?
The most common use of this feature would likely be to avoid merge conflicts in the change log. Solving just this would help a lot of the more active projects.