tmux: doesn't show up on the console

[alive4ever]

Maintainer: @diizzyy
Environment: x86_64, qemu, snapshot r6395-a70db57

Description:
When launching tmux directly on the OpenWrt console or serial, tmux doesn't show up.
Input works, but there is no tmux panel shown at all.

[mstorchak]

Maybe console doesn't provide all capabilities tmux requires.
How should the fix look like?

[alive4ever]

The fix may involves fixing procd console initialization to add capabilities tmux needs.

[alive4ever]

comparing output of stty on the openwrt console to actual linux console, the openwrt console output lacks the following capabilities:

-cmspar
-flusho
-extproc

[alive4ever]

procd seems to lack console initialization to set terminal configuration.
busybox init does have console_init.

[neheb]

I assume this is still an issue.

[mstorchak]

Is it a procd issue then?

[plntyk]

tested on
LEDE 17.01.7, 18.06.7, 19.07.3 and snapshot
on x86_64 VM and snapshot qemu Malta VM

as written before no input or output from tmux visible on serial or graphic output
but tmux itself works , with hotkeys
tmux capture-pane -pt 0 show hidden input if tmux isnt in foreground
tmux log on server side doesnt show obvious errors
tmux refresh-client -t/dev/ttyS0 does not work

running tmux inside a screen session works

[plntyk]

opened a bug report: https://bugs.openwrt.org/index.php?do=details&task_id=3170

might be related to permissions or features of device nodes involved