Cannot launch snap applications with cgroup v2

[Captive9199]

@timattrn

here is a launchpad bug here where it was decided that it was not a snap problem. Unfortunately, the bug report has not got the attention of anyone who seems to know what the problem is. You can disable new cgroups with a kernel parameter, which stops the error. I posted that tip in the bug report.

edit: There are now better workarounds at that bug report, and they hint that the login by the remote client is doing something wrong when setting up DBUS_SESSION_BUS_ADDRESS, which should be set by the systemd login flow somewhere. I think by the time the xsession is being set up, the root cause of the problem has already happened.

I came across this thread during my search for a solution for running ubuntu server 22.04 + firefox snap + geckodriver + python veenv + cron Similar or exactly the same as this post

Your reply was helpful, even if it did not apply to my use-case, because I am not supposed to have (by Ubuntu’s design) a running user-DBUS session , when I start scripts via cron.

I ended up removing the default firefox snap (has strict confinement) and installing the devmode snap with: snap install firefox --devmode

I do not recommend regular users to do this as per the documentation. However, this is enough for my use-case that involves running automated web checks on a set of websites for the next few decades

EDIT: 20220728-1224: there is another proposed solution in the post I linked, which involves using the linger feature of systemd/loginctl. It has much more appeal than using ‘devmode’ for production applications