If you’re using Gmane to read Python mailing-lists with an NNTP reader, you probably should read this:
Short version: If you’re reading mailing lists with an NNTP news reader via news.gmane.org, you should update your news reader to point to news.gmane.io instead.
If not, then sorry for the disturbance 
Thanks, Antoine. Note that, before you change news server names, you should probably ensure that you are up-to-date reading all of your subscribed groups (i.e. no unread messages) because the article numbers will likely be different on the new server and it may appear as if you haven’t read anything since the group was originally subscribed by gmane. If you know you have no unread messages, when you switch to the new server, you can just mark each group as read and start from there.
Ouch! We have a ton of gmane subscriptions on both MM2 and MM3. I’ve forwarded Lars’s blog posting to postmaster.
A followup: the gmane migration to news.gmane.io is almost complete. As best as I can tell, all of the gmane.comp.lang.python groups were successfully resubscribed to their corresponding mailing lists and are functioning correctly with minimal loss of messages with the exception of the mirror of the Python bugs list, (gmane.comp.python.bugs) which was waiting on a moderator approval. Thanks to help from Mark Sapiro, the request was approved and, as of a few minutes ago, bug tracker updates are again flowing to the gmane group. Unfortunately that means that there is a gap of about seven days in the gmane.comp.python.bugs group, from about 2019-01-08 until now. It’s probably not worth the effort to try to backfill the missing messages but. if anyone is motivated to try to do so, you could ask for guidance on the gmane.discuss group.
Further update: at the moment, gmane is not available while it is being moved to a new server (I probably should have waited to post the previous update). Lars reports that the move should be complete and gmane back up by around 21:00 GMT today (2020-01-15). https://lars.ingebrigtsen.no/2020/01/15/news-gmane-org-is-now-news-gmane-io/