On Ubuntu Linux 24.04.1, with tmux "set -g mouse on" clicking on window labels in status bar not consistent.

[palindsay]

Issue Description

I use tmux with mouse mode on, it allows quickly clicking on window label on status line to quickly switch tmux windows while I multitask and track progress of things happening in several terminals/tmux instances.

The mouse clicks aren't consistently recognized, it appears to be related to running several ninja / cmake builds happening (have 32 cores and 128gb ram). I also see the keystrokes to switch windows become unreliable.

I do not see this behavior with Gnome Terminal.

Expected Behavior

All mouse clicks and keystrokes recognized.

Actual Behavior

inconsistent when system has some load.

Reproduction Steps

Run a few builds like lllama.cpp and ffmpeg and attempt to switch between five different tmux windows.

Ghostty Logs

No response

Ghostty Version

~ ghostty --verion
info: ghostty version=1.2.3
info: ghostty build optimize=ReleaseFast
info: runtime=apprt.Runtime.gtk
info: font_backend=font.main.Backend.fontconfig_freetype
info: dependency harfbuzz=8.3.0
info: dependency fontconfig=21500
info: renderer=renderer.generic.Renderer(renderer.OpenGL)
info: libxev default backend=io_uring
info(os_locale): setlocale from env result=en_US.UTF-8
info(gtk): GTK version build=4.14.5 runtime=4.14.5
info(gtk): libadwaita version build=1.5.0 runtime=1.5.0
info: reading configuration file path=/home/plindsay/.config/ghostty/config
info(config): default shell source=env value=zsh
warning(gtk_ghostty_application): setting GDK_DEBUG=gl-disable-gles,gl-no-fractional,vulkan-disable
warning(gtk_ghostty_application): setting GDK_DISABLE=color-mgmt
info(gtk_ghostty_application): cgroup isolation disabled via config=config.Config.LinuxCgroup.single-instance
info(opengl): loaded OpenGL 4.6
info(io_exec): found Ghostty resources dir: /usr/share/ghostty
info(io_exec): shell integration automatically injected shell=termio.shell_integration.Shell.zsh
warning(gtk_ghostty_application): unimplemented action=apprt.action.Action.Key.cell_size
info(io_exec): started subcommand path=/bin/sh pid=1340740
info(io_exec): subcommand cgroup=-
info(stream): OSC 1 (change icon) received and ignored icon=~
warning(stream): unimplemented OSC command: change_window_icon

OS Version Information

Linux rastalinuxai.local 6.14.0-37-generic #37~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Thu Nov 20 10:25:38 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

(Linux only) Display Server

X11

(Linux only) Desktop Environment/Window Manager

No response

Minimal Ghostty Configuration

No config

Additional Relevant Configuration

set -g mouse on
unbind C-b
bind C-Space send-prefix
unbind-key C-b
set -g prefix 'C-z'
bind-key 'C-z' send-prefix
set-window-option -g mode-keys emacs
set-window-option -g xterm-keys on

# Enable mouse support for easy text selection
set-option -g mouse on

# Use Emacs keys for copy-mode
set-option -g mode-keys emacs

# Bind Ctrl-Space to start selection 
bind-key -T copy-mode-emacs C-Space send-keys -X begin-selection

# Bind M-w (Alt-w) to copy selected text
bind-key -T copy-mode-emacs M-w send-keys -X copy-selection-and-cancel

# For system clipboard access (copy to and paste from other applications)
set-option -g set-clipboard on

# Start windows and panes at 1, not 0
set -g base-index 1
set -g pane-base-index 1
set-window-option -g pane-base-index 1
set-option -g renumber-windows on

# Use Alt-arrow keys without prefix key to switch panes
bind -n M-Left select-pane -L
bind -n M-Right select-pane -R
bind -n M-Up select-pane -U
bind -n M-Down select-pane -D

# Shift arrow to switch windows
bind -n S-Left  previous-window
bind -n S-Right next-window

bind '"' split-window -v -c "#{pane_current_path}"
bind % split-window -h -c "#{pane_current_path}"

# enable activity alerts
setw -g monitor-activity on
set -g visual-activity on

# Center the window list
set -g status-justify centre

# use | and - to split the windows
bind-key | split-window -h
bind-key - split-window -v

# from http://endot.org/2011/12/06/my-tmux-configuration/
# keybindings to make resizing easier
bind -r C-h resize-pane -L
bind -r C-j resize-pane -D
bind -r C-k resize-pane -U
bind -r C-l resize-pane -R

# Update window name frequently
set-option -g status-interval 5      

# Automatically rename windows
set-option -g automatic-rename on  

# Rename format to use the directory's basename
set-option -g automatic-rename-format '#{b:pane_current_path}'

new-session -d -s tmuxsess
select-window -t tmuxsess:1

# Set Emacs mode
set-option -g status-keys emacs

I acknowledge that:

• I have reviewed the FAQ and confirm that my issue is NOT among them.
• I have searched the Ghostty repository (both open and closed Discussions and Issues) and confirm this is not a duplicate of an existing issue or discussion.
• I have checked the "Preview" tab on all text fields to ensure that everything looks right, and have wrapped all configuration and code in code blocks with a group of three backticks (```) on separate lines.

[rokke-git]

you should wrap your tmux config in ``` backticks so that the comments stop rendering as headers...

I'm seeing the same issue on my system. it's not that the clicks aren't being recognized, they're just not changing the focused pane: if you try to interact with another program which uses a mouse, (such as selecting text in nvim), you can see that the mouse is sending input but not changing the focused pane

I've gotten somewhat used to it, the "inconsistency" you're feeling is that two clicks are required, but a double- or triple- click will usually count as one thing. so you have to click, let the double click timeout, then click again for it to send a click and then also focus the pane.

have no idea why one would want to click on tmux panes/windows without focusing them though...

[palindsay]

Thanks for response. I have several terminal windows with tmux, different processes running during testing/development workflow (one or machines). I often quickly click on another tmux window on specific screen as a quick way for me to check state of a particular running process , typically clicking back to another window where I am working. Good or bad, this behavior I got used to using gnome terminal.

[rokke-git]

(note that I'm saying I agree with you; I'm just running into the same problem...)