I was trying to re-attach to a long-running tmux session to check up on a python web-application. However tmux attach
claims that there is no running session, and ps
shows a tmux
process (first line), but with a question mark instead of the pts
number.
What does this mean—is this tmux session permanently lost, and what could have caused it? Is there still a way to look at the current state of the python process, spawned in the tmux session and running in pts/19
(second line)?
[mhermans@web314 ~]$ ps -ef | grep mhermans
mhermans 16709 1 0 Mar04 ? 00:26:32 tmux
mhermans 8526 16710 0 Mar04 pts/19 00:20:04 python2.7 webapp.py
root 9985 6671 0 10:18 ? 00:00:00 sshd: mhermans [priv]
mhermans 10028 9985 0 10:18 ? 00:00:00 sshd: mhermans@pts/16
mhermans 10030 10028 0 10:18 pts/16 00:00:00 -bash
mhermans 16247 10030 6 10:28 pts/16 00:00:00 ps -ef
mhermans 16276 10030 0 10:28 pts/16 00:00:00 grep mhermans
mhermans 16710 16709 0 Mar04 pts/19 00:00:00 -bash
mhermans 16777 16709 0 Mar04 pts/21 00:00:00 -bash
Best Answer
Solution courtesy of the Webfaction-support:
As the process was still running, the issue was a deleted socket, possibly caused by a purged tmp-directory.
According to the
tmux
mapage:So sending the signal and attaching works: