It came up in https://bugs.python.org/issue32690 that it's not at all clear how to revert commits to a maintenance branch if we decide that a change shouldn't have been backported after all.

Transferring over my notes from that issue to be cleaned up and added to the dev guide:

• check out the branch of interest and ensure it's up to date
• git checkout -b bpo-32690-revert-3.6-backport
• git revert 9105879bfd7133ecbac67f3e9c0bacf6e477de5a
• edit commit message as appropriate
• create a PR targeting the branch of interest: [3.6] Revert "bpo-32690: Preserve order of locals() (GH-5379)" cpython#5439