I am using tmux on a Gentoo Linux hardened system running kernel 3.18.9. When I run programs that display borders on the terminal such as
nmon directly under my terminal or under
screen, they display fine.
However, when I run such programs under
tmux, the borders appear like Unicode error characters and some parts of the program output are mangled.
I've already tried setting different values for
$TERM environment variable and it doesn't work. I can't figure out what does
tmux have that somehow makes its terminal different from
screen. What's happening here?