Running ghostty with --gtk-single-instance=true only spawns instance once out of twice

[xuhzs]

When using ghostty on arch + niri, I noticed that when running ghostty --gtk-single-instace=true (which is the default when running outside cli according to doc here), it only creates a new window once out of twice. Both run generates the same output and does not return any error, but only the second run will open up a new window.

When I run it with ghostty --gtk-single-instance=false, this problem does not exist.

Not sure if this is a bug or a niri or me problem, so posting as a question first.

$ ghostty --gtk-single-instance=true
info: ghostty version=1.2.3-arch2
info: ghostty build optimize=ReleaseFast
info: runtime=apprt.Runtime.gtk
info: font_backend=font.main.Backend.fontconfig_freetype
info: dependency harfbuzz=12.3.0
info: dependency fontconfig=21701
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=4.20.2 runtime=4.20.3
info(gtk): libadwaita version build=1.8.1 runtime=1.8.2
info: reading configuration file path=/home/${USER}/.config/ghostty/config
info(config): loading config-file path=/home/${USER}/.config/ghostty/config-dankcolors
info(config): default shell source=env value=/usr/bin/zsh
warning(gtk_ghostty_application): setting GDK_DEBUG=
warning(gtk_ghostty_application): setting GDK_DISABLE=gles-api,vulkan

$ ghostty --gtk-single-instance=true
info: ghostty version=1.2.3-arch2
info: ghostty build optimize=ReleaseFast
info: runtime=apprt.Runtime.gtk
info: font_backend=font.main.Backend.fontconfig_freetype
info: dependency harfbuzz=12.3.0
info: dependency fontconfig=21701
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=4.20.2 runtime=4.20.3
info(gtk): libadwaita version build=1.8.1 runtime=1.8.2
info: reading configuration file path=/home/${USER}/.config/ghostty/config
info(config): loading config-file path=/home/${USER}/.config/ghostty/config-dankcolors
info(config): default shell source=env value=/usr/bin/zsh
warning(gtk_ghostty_application): setting GDK_DEBUG=
warning(gtk_ghostty_application): setting GDK_DISABLE=gles-api,vulkan

[17o29562381-byte]

So ghostty popups up twice and the second session has no problems. Well just "comb it out" because its always the first instance that has a problem. Its like that static issue when writing C/C++ code it doesn't make sense so maybe you have to make it with the volatile type because static cannot change.
so you config file has to be volatile is what I am sayin' it cannot be a static file.

[davidaf3]

Also happens when running ghostty +new-window. I think this is an issue with the GTK renderer, because running with GSK_RENDERER=cairo fixes the problem for me.

[xatier]

@davidaf3 do you mean GSK_RENDERER=cairo ghostty --gtk-single-instance=true? I still observe the same issue on my host.

[davidaf3]

Yes, in my case the problem was this GTK bug that should be fixed in 4.22. It was a Wayland specific bug, so your issue must have a different cause.

[xatier]

Seeing similar issue on Arch with Awesome WM. The default configuration will enable gtk-single-instance with the detect mode, which makes the window spawning very slow if you are using a tiling WM. Setting gtk-single-instance=false in the config file would always create new instances but it's much faster.

I suspect the issue is somewhere between dbus, based on my strace investigation.

$ ghostty +version
Ghostty 1.2.3-arch3

Version
  - version: 1.2.3-arch3
  - channel: tip
Build Config
  - Zig version   : 0.14.1
  - build mode    : builtin.OptimizeMode.ReleaseFast
  - app runtime   : apprt.Runtime.gtk
  - font engine   : font.main.Backend.fontconfig_freetype
  - renderer      : renderer.generic.Renderer(renderer.OpenGL)
  - libxev        : io_uring
  - kernel version: 6.18.9-arch1-2
  - desktop env   : other
  - GTK version   :
    build         : 4.20.3
    runtime       : 4.20.3
  - libadwaita    : enabled
    build         : 1.8.4
    runtime       : 1.8.4
  - libX11        : enabled
  - libwayland    : enabled

[jcollie]

Ghostty should be run once from a systemd user unit that starts up at login. New windows can then be created by running ghostty +new-window if you're not using a DE that supports DBus activation. This "hides" the GTK startup cost in while you are logging and and new window creation is as fast as you could want it. See the docs for more details:

https://ghostty.org/docs/linux/systemd

Also, I don't think that --gtk-single-instance=true works quite the way that you think. When --gtk-single-instance=true Ghostty will use DBus to make sure that there's only once instance of Ghostty running. If there's already a Ghostty instance running the new Ghostty sends a signal to the old Ghostty to create a new window and then quits. Otherwise it finishes the rest of the startup sequence. ghostty +new-window only sends a signal to an existing Ghostty instance to create a new window.

If you don't have DBus set up quite right, including the DBus activation services and the GTK desktop portal Ghostty startup can indeed be quite slow. Unfortunately tiling window managers, with their DIY/no batteries included ethos, tend to make it hard to get that right.

[jcollie]

Yes, it's a hard dependency. Ghostty on GTK only uses DBus for IPC. Even if Ghostty didn't use it directly, GTK is highly dependent on DBus.

[xatier]

Got it, thanks for the clarification.

[RNBermudez]

I am experiencing the same issue launching with ghostty +new-window with the systemd unit running:

> systemctl --user status app-com.mitchellh.ghostty.service
● app-com.mitchellh.ghostty.service - Ghostty
     Loaded: loaded (/usr/lib/systemd/user/app-com.mitchellh.ghostty.service; enabled; preset: enabled)
     Active: active (running) since Thu 2026-04-09 09:48:18 -03; 8min ago
 Invocation: 9f1d1cf6d4c2400188d272eb606ed0fb
   Main PID: 413373 (ghostty)
      Tasks: 9 (limit: 18992)
     Memory: 466.9M (peak: 470.1M)
        CPU: 13.192s
     CGroup: /user.slice/user-1000.slice/user@1000.service/app.slice/app-com.mitchellh.ghostty.service
             └─413373 /usr/bin/ghostty --gtk-single-instance=true --initial-window=false

Apr 09 09:56:34 niffelheim ghostty[413373]: info(io_exec): pty fd closed, read thread exiting
Apr 09 09:56:34 niffelheim ghostty[413373]: info(surface): surface closed addr=558ef6797be0
Apr 09 09:56:37 niffelheim ghostty[413373]: info(opengl): loaded OpenGL 4.6
Apr 09 09:56:37 niffelheim ghostty[413373]: info(io_exec): found Ghostty resources dir: /usr/share/ghostty
Apr 09 09:56:37 niffelheim ghostty[413373]: info(io_exec): shell integration automatically injected shell=.zsh
Apr 09 09:56:37 niffelheim ghostty[413373]: warning(gtk_ghostty_application): unimplemented action=.cell_size
Apr 09 09:56:37 niffelheim ghostty[413373]: info(io_exec): started subcommand path=/bin/sh pid=416983
Apr 09 09:56:38 niffelheim ghostty[413373]: info(io_exec): pty fd closed, read thread exiting
Apr 09 09:56:38 niffelheim ghostty[413373]: info(surface): surface closed addr=558ef6797be0
Apr 09 09:56:42 niffelheim ghostty[413373]: info(page_list): adjusting page capacity=.{ .cols = 170, .rows = 273, .styles = 128, .hyperlink_bytes = 384, .grapheme_bytes >

The only workaround I found for this is to set gtk-single-instance = false, which results in very slow startup times (1+ seconds).

I am on:

• OS: CachyOS
• Niri: niri 25.11 (b35bcae)
• Wayland: 1.24.0-1.1
• GTK4: 1:4.20.4-1.1
• Ghostty: Ghostty 1.3.1-arch1.1

[davidaf3]

@RNBermudez this issue should be fixed with GTK 4.22

[RNBermudez]

@davidaf3 Ahh good catch! I read the bug you linked, but I totally missed the version mismatch. My bad! I just upgraded, and it appears to be fixed now. Thanks!