>>/9804/
Showed errors:
> # criu dump --shell-job --tcp-established -t 27184
> Error (criu/file-lock.c:110): Some file locks are hold by dumping tasks! You can try --file-locks to dump them.
> Error (criu/cr-dump.c:1781): Dumping FAILED.
> # # where PID 27184 = "/home/ubuntu/gs-venv/bin/python /home/ubuntu/gs-venv/bin/grab-site https://www.canterlot.com/"

Showed zero errors, but it killed the grab-site process:
> # criu dump --shell-job --tcp-established --file-locks -t 27184
> # # made a 56-MB dump (find PID by "ps aux | grep grab-site | tail -n2")

Restoration failed (moved to "/z9/warc/012/criu/new2/"):
> # criu restore --shell-job --tcp-established
> Error (criu/cr-restore.c:1480): 27184 killed by signal 11: Segmentation fault
> Error (criu/cr-restore.c:2447): Restoring FAILED.
> # # so try without --file-locks and maybe it somehow still works?
> # # same "Dumping FAILED" error with "sudo criu dump --shell-job --tcp-established -t 29094"
> # # will see if it can somehow be restored

Tested on this OS version:
> $ lsb_release -a
> [...]
> Description: Ubuntu 22.04.3 LTS
> Release: 22.04
> Codename: jammy