Maybe not so much for phoenix, but for some other libraries with a lot of stuff not merged to master (svn release), you may desire to get the first merge point in git some place back in history. If you find your most resent commit where the source trees in develop and master are equal or are acceptable to merge to master. Then you can do.
git checkout master git merge --no-ff <commit-sha1-you-want-to-merge-to-master> git status # resolve conflicts if any git commit -am "merged develop->master to get first git merge point"
I use the --no-ff option out of habit, as that is what I most often want to do. When merging feature branches into develop or develop into master --no-ff ensure that you get a new commit for the merge, and that the merge is not simply a fast-forward along the merged-in-branch which would include all your intermittent commits in the branch you merge to.
That worked a treat for me, many thanks, I'll see if I can add this to the Wiki as it seems to be something everyone pretty much will need to do. John.