sixel inside tmux and ssh workaround

[galchinsky]

Windows Terminal version

1.22.240823002-preview

Windows build number

10.0.22631.4037

Other Software

tmux next 3.5 (latest so far 34807388b064 commit built with --enable-sixel)

Steps to reproduce

In WSL2 tab img2sixel logo.png just works, hurray. It also works if I ssh to a remote server from the WSL2 tab.

Then I start tmux and run the same command. It outputs in a fallback mode

$ img2sixel logo.png
SIXEL IMAGE (12x6)
++++++++++++
++++++++++++
++++++++++++
++++++++++++
++++++++++++

Then I (similarly to a suggestion at https://github.com/wez/wezterm/issues/1236)

• go to a Windows "Command Prompt" tab
• ssh to WSL2 from there
• create tmux session and type "img2sixel logo192.png" .

sixel output starts to work, even on a remote server + tmux combination. This is weird, because if it wasn't so, I would think it's a tmux bug. But now it seems something is off with how WSL2 tab works.

Expected Behavior

sixel output inside tmux

Actual Behavior

tmux outputs

SIXEL IMAGE (12x6) ++++++++++++ ++++++++++++ ++++++++++++ ++++++++++++ ++++++++++++

but works correctly if ssh to WSL2 from Windows