Comment 7 for bug 1784872

There are plenty of discussions on the topic in general around all of linux, like:
- https://superuser.com/questions/272061/reload-a-linux-users-group-assignments-without-logging-out
- https://serverfault.com/questions/74934/refresh-supplementary-group-memberships-without-logging-in-again
- https://unix.stackexchange.com/questions/18796/how-to-apply-changes-of-newly-added-user-groups-without-needing-to-reboot

But none of the solutions there (sudo su / su / newgrp) would be safe to do from a package install POV - and furthermore none of these would e.g. fix your desktop environment around the shell that did the install.

As I said maybe there is a mechanism that I don't know, so maybe it is worth asking the mailing list.
I'll ask on the mailing list if I miss a mechanism to do this better.