If I run tmux as root, it runs normally and fully functional. I created a couple users, and it will not run as any of the users.
create session failed: : No such file or directory
I checked the outside $TERM is xterm and inside $TERM is screen as FAQs suggest that is most common cause of problems.
I've used tmux regularly on many different systems, but I on this VPS I can't figure out what's up... A little help, please?
EDIT: Thanks to Jay's helpful advice about strace, I found a permissions problem with /dev/pty*. I fear this won't be a useful post for many others as it seems kind of a one-off problem.
strace -f -e trace=file tmux
32000 open("/dev/ptmx", O_RDWR) = -1 EACCES (Permission denied)
32000 open("/dev/ptyp0", O_RDWR) = -1 EACCES (Permission denied)
32000 open("/dev/ptypf", O_RDWR) = -1 EACCES (Permission denied)
32000 open("/dev/ptyq0", O_RDWR) = -1 ENOENT (No such file or directory)