---BEGIN UPGRADE MESSAGE---
The directory /var/lib/mailman/qfiles contains files. It needs to be empty for the upgrade work properly. Please either flush the queue (by way of mailmanctl start, then stopping it and redoing the upgrade when it is finished) or remove those files. Note that removing the files will lose some emails sent to lists.
---END UPGRADE MESSAGE---
But nowhere does it tell you how to stop the flow of messages into mailman, so that the rogue messages can be dealt with without new ones creeping into the mix.
The message says:
---BEGIN UPGRADE MESSAGE--- mailman/ qfiles contains files. It needs to be empty for the upgrade work properly. Please either flush the queue (by way of mailmanctl start, then stopping it and redoing the upgrade when it is finished) or remove those files. Note that removing the files will lose some emails sent to lists.
The directory /var/lib/
---END UPGRADE MESSAGE---
But nowhere does it tell you how to stop the flow of messages into mailman, so that the rogue messages can be dealt with without new ones creeping into the mix.