How to bring in the upstream github/develop

What is the best way to bring in github/develop ?

The github/develop upstream is so different from the original master that even merging it to github/master does not work.

@ban I discussed this; it seems that so many files were moved around, that git merge is not working any more (or at least not without tremendous manual interaction).

Given that we have identified the files that we changed in order to adjust the code for Phoenix, should we take github/develop, branch of our own (new) dev tree from there, and then manually bring in the changes for the files that we adjusted based on the old/original github/master branch?

That would not keep the commit history for our changes, but I'm not git-proficient enough to know how to do it otherwise.

@ban: any suggestions or can you help here?

Best.