Visual glitches in TUI apps

[sebastianstudniczek]

I noticed that in some apps, for example OpenCode or Copilot (didn't notice such issue in Neovim) there are visible visual glitches.
Altough, it's not happening constantly, sometimes when I open OpenCode then there are no such glitches.
I don't experience it in wezterm, windows terminal or alacritty

Do you know maybe what might be the reason?

Tested both version with/without wsl bypass and they are still present (without tmux).

OS: WSL Ubuntu
Version: 0.33

Recording.2026-09-10.142653.-.Trim.-.Trim.mp4

[sudo-tee]

Thanks for the report. I will have a look

I don't have this issue so I will have to investigate

[sebastianstudniczek]

Thanks, let me know if/how I can provide more details

[sudo-tee]

I created a PR with a potential fix.

#25

I still need to ensure it does not introduce performance issues but if you have time to check if that resolve the issue.

I was able to reproduce the issue with a synthetic benchmark and can confirm it worked for that specific case, but I can't verify in opencode as I don't have the issue in opencode

[sebastianstudniczek]

So I tested it and flickering is gone, but there are still rows with different colors presented. I am wondering whether it has something to do with handling terminal background color.

I have this in my config:

  theme = {
		terminal = {
			background = "#191A1C",
		},
	},

The same background color is set in windows terminal.

When I leave the default color then it's fine. I also noticed that in hollow there is no system theme available in opencode as opposed to windows terminal for example (which I have set up by default in tui.json config for opencode)

Video.Project.mp4

[sudo-tee]

Thanks for testing. The background option is actually a very good information to help me debug

[sudo-tee]

@sebastianstudniczek

I think I found the issue.

There was a colorSheme callback not implemented so hollow was doing nothing when ghostty reported a default colorscheme.

Let's hope it fixes your remaining issue :)

You can test it in the same MR the build links should be updated

[sebastianstudniczek]

Yes, it's working now, thanks a lot :D

[sebastianstudniczek]

Sorry, I gave it another try today for a longer period of time and unfortunately the visual glutches are still present.

But for some reason when the application occupies half the screen (there is second application on the same monitor) then the flickering is gone

[sudo-tee]

@sebastianstudniczek what is the qhwn app. I can give it a try

Can you give me your shell variables

echo $COLORTERM and echo $TERM

[sebastianstudniczek]

Sorry, it should be "when" xd

Here is a demo of this behavior:

Video.Project.1.mp4

[sudo-tee]

@sebastianstudniczek I created another build. I was able to reproduce the issue only once before the fix.

I think this time it will work as in opencode now the background is darker when opening the session switcher, where before it would use the configured bg in your theme. I compared with windows terminal and wezterm and now hollow has the same color and behavior.

[sebastianstudniczek]

Yes, it's working now! Thanks a lot

[sudo-tee]

Awesome, I will merge and create a release then.