Assuming I'm right and there are no more blockers for the migration (see my other email to this list on that topic), here is my current thinking on the steps necessary to migrate (I am CC'ing people I'm hoping can help me out with this plan and bolded their names; anything without someone's name is on me to do).
  1. Make the hg repo read-only (Benjamin, Georg, or Antoine?)
  2. Rename python/cpython to python/cpython-mirror
  3. Create a new python/cpython project and add relevant webhooks/integrations
    1. CLA bot
    2. Travis
    3. Codecov
  4. Migrate the hg repo and push it to GitHub (Senthil?)
  5. Update docs.python.org to build from GitHub (push https://github.com/python/psf-salt/pull/91; Berker?)
  6. Get buildbots to build from GitHub (Zach?)
  7. Updates posted to #python-dev (R. David?)
  8. Commits sent to python-checkins
  9. Gather commit IDs from hg repo
  10. Push update to hg.python.org/lookup (Benjamin, Georg, or Antoine?)
  11. Add configuration files for services from https://github.com/brettcannon/cpython-ci-test
    1. Travis
    2. Codecov
If I'm missing anything please let me know (everything else I know isn't really time-critical for accepting commits). Once we agree that these are the steps required and people whose help I need/want are on board then I will schedule with python-committers and the requisite release managers to get a date and verify with the people helping me. Then we can do the migration! I know there seem like there are a lot of steps, but a lot of this is parallelizable (e.g. once step 1 is done, steps 2-4 can occur, and after step 4 then the rest of the steps can happen in any order).