#11256 merged 784f52a into 3.7 from terryjreedy/news37 as 93f5694. The latter was pulled and merged into the 3.7 branch of my local repository. It is also part of the 3.7.3 release. Git says that 784f52a is also an unmerged commit on the 3.7 branch. git status says all is fine. Perhaps I committed the same diff to two branches. The diff for this is empty, but I suspect it would not be good for the DAG graph. I will inquire on core-mentorship as to what to do so I can do clean manual backports again.

@terryjreedy, looking at PR #11256 it appears 784f52a was the basis for the squash merge with id 93f5694. So there is no need to push anything upstream. Chances are you inadvertently merged it to your local 3.7 branch somewhere along the line. You just need to clean up that local branch so that it matches what is upstream. Assuming you have no pending other local changes on your 3.7 branch, one way to fix things would be to do something like:

git checkout 3.7
git reset --hard  784f52a^   # This trims the branch to the parent of 784f52a
git pull  # pull all the upstream changes to the branch since then

Thank you. When I enter git reset --hard 784f52a^, I got a prompt more?. Once I discovered to enter a space to not add anything, I was able to produce #13067, which appears to be OK.