It looks like 16.2 uses this kolla_extend_start file: https://opendev.org/openstack/tripleo-common/src/branch/stable/train/container-images/kolla/horizon/extend_start.sh while 16.1 uses: https://opendev.org/openstack/kolla/src/branch/stable/train/docker/horizon/extend_start.sh it seems that the first one is incomplete
The SITE_PACKAGES env var is not being set correctly in the tripleo-common kolla extend_start.sh script. A a fix has been already submitted to master, we will proceed to the backport as soon as it gets merged.
https://review.opendev.org/c/openstack/tripleo-common/+/793185 has merged upstream.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Red Hat OpenStack Platform (RHOSP) 16.2 enhancement advisory), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHEA-2021:3483