Tmux Orphaned Socket

tmux ls failing with error connecting to /tmp/tmux-<uid>/default (No such file or directory) does not mean the sessions are gone. A running tmux server keeps its windows alive in memory even after its own socket file is deleted out from under it — deleting a Unix domain socket file doesn't touch the process holding it open, it only blocks new connections. This is the usual outcome of a /tmp cleanup (a cron sweep, an agent-run script, a manual rm -rf /tmp/*) that didn't exclude /tmp/tmux-*.

Diagnose, don't assume