Session spawned in TTY does not detect X server

[talhaahussain]

Hi all, I'm pretty new to tmux so I'm unsure if this is a real issue, or if this is intended behaviour, which is why I decided to post this here instead of opening an issue.

If I spawn a tmux session in TTY (where echo $TERM gives returns linux), detach from it and start X server, when I reattach to the session inside the X server instance, and attempt to run any program that requires X server to be running, I get an error, telling me that the program cannot open X display. However, running the same program outside of this tmux session works fine, within or outside of another tmux session. I originally discovered this issue when running the feh image viewer on a tmux session that was born in TTY - feh would not start since it could not open X display.

Is this a genuine issue, or a misunderstanding on my part of how tmux works? Also, please let me know if I should improve my formatting, etc.

I'm running Arch Linux, using xmonad as my window manager, and using the default tmux configuration. Let me know if I should post configuration files, logs, or anything else.

Many thanks!