Just discovered this tool while doing a messy rebase, and can't believe it has had very little discussion I can find.

https://github.com/mhagger/git-imerge

No previous commentary on it so far on HN:

https://hn.algolia.com/?query=git%20imerge&dateRange=all

So, can anyone find any interesting discussion about this tool?

If you'd prefer reading rather than listening to the talk, here's an article which covers some of the same concepts:

https://wilsonmar.github.io/git-imerge/

The crux of it is that the tool does an efficient pairwise merge of all commits from the donor branch onto master. It can also be configured to run the test suite to detect conflicts.

Then you resolve conflicts in pairs of commits, which is only a small amount of work. The histories of your individual resolutions are preserved, so you can pause and resume the task.