More specifically,

How can I discover what process had ran under a PID, if the process ran under a graphical session which restarted because of a crash, and then I killed it (the session)? It’s not in the session’s logs (it was COSMIC, so I ran it with RUST_BACKTRACE=1 and redirected the output to a file; nothing, other than a PID for a process that’s no longer there).

The error in the COSMIC logs was “PID 22842 does not belong to any known session”. I have reason to believe the process is a foot terminal launched by a systemd user service, which ran a script that launched the terminal(s). But I need to be sure, so I know what I’m dealing with, and I can approach it the right way.

Any help, info, or pointers would be greatly appreciated. Thank you.