Tmux - error: NoGraphicsCapability

[steinbrueckri]

Hi,

first of all, thanks for this great project — I really love the idea of viewing PDFs directly in the terminal with Kitty’s image protocol.

However, I’m running into an issue when trying to use fancy-cat inside tmux. When I run it, I immediately get the following error: error: NoGraphicsCapability

Outside of tmux, fancy-cat works perfectly fine. Inside tmux, it consistently fails with this error. I suspect it might be related to how tmux handles the Kitty graphics protocol, but I’m not sure.

• Terminal: kitty 0.42.1
• Tmux version: tmux 3.5a
• OS: macOS Sequoia 15.5 arm64

Let me know if I can provide more information to help debug this.
Thanks again!

[freref]

Hi! This is a known issue with tmux. Can you try this workaround?

[steinbrueckri]

noop 😭

[j4james]

As far as I understand, the allow-passthrough option doesn't actually do anything by itself. It just permits an application to use the tmux passthrough sequence to communicate directly with the connected terminal. So if your app hasn't actually been designed to make use of that tmux sequence, it's not going to help.

[freref]

Thanks for trying, I don't use tmux myself, but I'll add this to my todo.

[freref]

Adding tmux support is not as trivial as I expected. I've started work here rockorager/libvaxis#260.

[freref]

Will be testing in this branch https://github.com/freref/fancy-cat/tree/feature/tmux-support.