Hi Folks, as the subject goes, my installation has been hit by an old bug: https://bugs.launchpad.net/oslo.messaging/+bug/1828841 (bug details not important, linked here for background) I am using Stein, deployed with recent Kolla-built source-based images (with only slight modifications compared to vanilla ones). Kolla's procedure for building source-based images considers upper constraints, which, unfortunately, turned out to be lagging behind a few releases w.r.t. oslo.messaging at least. The fix was in 9.7.0 released on May 21, u-c still point to 9.5.0 from Feb 26 and the latest of Stein is 9.8.0 from Jul 18. It seems oslo.messaging is missing from the automatic updates that bot proposes: https://review.opendev.org/#/q/owner:%22OpenStack+Proposal+Bot%22+project:op... Per: https://opendev.org/openstack/releases/src/branch/master/doc/source/referenc... this upper-constraint proposal should be happening for all releases. I would be glad if someone investigated why it happens(/ed) and audited whether other OpenStack projects don't need updating as well to avoid running on old deps when new are awaiting for months. :-) Please note this might apply to other branches as well. PS: for some reason oslo.messaging Stein release notes ( https://docs.openstack.org/releasenotes/oslo.messaging/stein.html ) are stuck at 9.5.0 as well, this could be right (I did not inspect the sources) but I am adding this in PS so you have more things to correlate if they need be. -yoctozepto