XDG_RUNTIME_DIR not set & /run/user/1000 not created

[spflanze]

I have two issues I believe are related:

1. The global variable XDG_RUNTIME_DIR is not set to anything.

2. There is only one user on this newly installed Ubuntu 22.04 OS. It would be expected the user number for it is 1000. This is verified by the global $UID being set to that number as expected. But the directory /run/user/1000 does not exist. The directory /run/user/ is empty.

For an unknown reason pam_systemd does not set XDG_RUNTIME_DIR, and does not make the directory /run/user/1000, upon login.

I believe the lack of the temporary data directory at /run/user/1000 is causing firefox, and possibly other snap applications, not to run. The error I get when I attempt to run firefox from the Konsole terminal emulator is:

2022/07/03 16:49:54.424008 cmd_run.go:1053: WARNING: cannot start document portal: Expected portal at "/run/user/1000/doc", got "/home/stephen/.cache/doc"
/system.slice/sddm.service is not a snap cgroup

I made the syslog file available for download at: https://www.mediafire.com/file/4duykf9u2mgwa23/Target_Computer_syslog_2022-07-16.zip/file .

The file system is ZFS. It was installed using a version of rlaager's procedure I modified to meet my needs. rlanger's procedure is posted here:
https://openzfs.github.io/openzfs-docs/Getting%20Started/Ubuntu/Ubuntu%2022.04%20Root%20on%20ZFS.html
The latest version of my modifications can be downloaded here:
https://www.mediafire.com/file/2w8mdb96tbzslub/Ubuntu_22.04_Root_on_ZFS_Encryption.odt/file
My modifications are working now to enable booting Ubuntu 22.04. The generic boot options, however, do not work. One of the two Ubuntu 22.04 boot options grub presents at boot time has to be chosen for a successful boot.

What could be blocking the setting of XDG_RUNTIME_DIR set, and the creation of the directory /run/user/1000 ? What must be done for it to happen as it should be?

[spflanze]

To be able to run firefox I had to disable cgroup. I disabled it by following the directions in the c25 post at https://bugs.launchpad.net/ubuntu/+source/snapd/+bug/1951491.
Although firefox runs, it starts up with many permission denied errors. For these I will open a new thread.