RFD: best way to automatically rewrite a git DAG as a linear history?

Does the git toolset currently support rewriting a restricted git DAG as a linear history in a completely automated way?

I understand that git rebase --root will attempt to rebase a DAG, but as far as I can tell any conflicts that occur during the rebase require a manual intervention to correct. My goal is a completely automated rewrite.

I guess some might be sceptical that a sane automated rewrite is impossible, but I am insane enough to think it might actually be possible.

I have prototype that implements an algorithm that does this [ for a restricted class of DAG of interest to me ], so I can't be completely insane, but if other people have already knocked the corners of this particular wheel, I'd be interested to learn of their efforts.

Regards.

jon