waybar stops talking to hyprland ipc after a display is plugged in/out

[gottaeat]

$ Hyprland --version
Hyprland 0.47.2 built from branch  at commit 882f7ad7d2bbfc7440d0ccaef93b1cdd78e8e3ff  (version: bump to 0.47.2).
Date: Sun Feb 2 00:47:17 2025
Tag: v0.47.2, commits: 5767
built against:
 aquamarine 0.7.2
 hyprlang 0.6.0
 hyprutils 0.5.0
 hyprcursor 0.1.11
 hyprgraphics 0.1.2

$ waybar --version
Waybar v0.12.0

config.jsonc:

{
    "layer": "top",
    "position": "top",
    "height": "",
    "width": "",
    "spacing": 4,
    "modules-left": [
        "hyprland/workspaces"
    ],
    "modules-right": [
        "hyprland/language",
        "tray"
    ],
    "hyprland/language": {
        "format": "{short}"
    },
    "tray": {
        "icon-size": 21,
        "spacing": 1
    }
}

hyprland display config:

monitor = DP-1, 3840x2160@60, 0x0, 1.5, bitdepth, 8
monitor = HDMI-A-1, 1920x1080@60, 2560x0, 1, bitdepth, 8, vrr, 0

full process log:

[2025-03-08 15:09:48.443] [info] Using configuration file /home/user/.config/waybar/config.jsonc
[2025-03-08 15:09:48.445] [info] Discovered appearance 'dark'
[2025-03-08 15:09:48.445] [info] Using CSS file /home/user/.config/waybar/style.css
[2025-03-08 15:09:48.447] [info] Hyprland IPC starting
[2025-03-08 15:09:48.447] [info] Loading persistent workspaces from Hyprland workspace rules
[2025-03-08 15:09:48.476] [info] Loading persistent workspaces from Hyprland workspace rules
[2025-03-08 15:09:48.513] [info] Bar configured (width: 2560, height: 24) for output: DP-1
[2025-03-08 15:09:48.513] [info] Bar configured (width: 1920, height: 24) for output: HDMI-A-1
[2025-03-08 15:09:48.519] [info] Bar configured (width: 1920, height: 24) for output: HDMI-A-1

# - - HDMI-A-1 DISCONNECTED HERE - - #

# - - HDMI-A-1 PLUGGED BACK IN - - #

** (waybar:32723): CRITICAL **: 15:10:06.567: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-03-08 15:10:06.567] [info] Hyprland IPC stopping...

** (waybar:32724): CRITICAL **: 15:10:06.568: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-03-08 15:10:06.568] [info] Hyprland IPC stopping...

** (waybar:32725): CRITICAL **: 15:10:06.569: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-03-08 15:10:06.569] [info] Hyprland IPC stopping...

** (waybar:32726): CRITICAL **: 15:10:06.569: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-03-08 15:10:06.570] [info] Hyprland IPC stopping...

** (waybar:32733): CRITICAL **: 15:10:06.571: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-03-08 15:10:06.571] [info] Hyprland IPC stopping...

** (waybar:32734): CRITICAL **: 15:10:06.571: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-03-08 15:10:06.571] [info] Hyprland IPC stopping...

** (waybar:32735): CRITICAL **: 15:10:06.572: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-03-08 15:10:06.572] [info] Hyprland IPC stopping...

** (waybar:32736): CRITICAL **: 15:10:06.573: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-03-08 15:10:06.573] [info] Hyprland IPC stopping...

** (waybar:32737): CRITICAL **: 15:10:06.574: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-03-08 15:10:06.574] [info] Hyprland IPC stopping...
[2025-03-08 15:10:06.575] [info] Bar removed from output: HDMI-A-1
[2025-03-08 15:10:07.179] [info] Loading persistent workspaces from Hyprland workspace rules
[2025-03-08 15:10:07.202] [info] Bar configured (width: 1920, height: 24) for output: HDMI-A-1
[2025-03-08 15:10:07.205] [info] Bar configured (width: 1920, height: 24) for output: HDMI-A-1

after the last logline none of the hyprland/* modules work in any of the outputs.

[ctilley83]

I have a similar issue, but the trigger is when hypridle turns on the display after idle. It seems waybar is looking for the display before it has time to fully wake.

[123Daktary]

Hello! I'm also having a similar issue as OP but I'm facing this issue when I'm manually disabling my laptop's monitor.

Steps to reproduce:

1. A multi-monitor setup is needed. Start with one monitor disabled and without waybar running as a background process
2. Run "waybar" in a terminal window
3. In a new terminal window, enable the monitor via Hyprland command
4. Disable the monitor via Hyprland command

Issue:
After a monitor is disabled, waybar doesn't refresh the "hyprland/workspaces" and "hyprland/window" modules anymore for the active monitor. All other modules seem to work fine, like "clock", "tray", "pulseaudio", etc.

Outputs:

• Step 2

Terminal 1

$ waybar
[2025-03-11 17:18:58.771] [info] Using configuration file /home/<user>/.config/waybar/config.jsonc
[2025-03-11 17:18:58.774] [info] Using CSS file /home/<user>/.config/waybar/style.css
[2025-03-11 17:18:58.781] [info] Hyprland IPC starting
[2025-03-11 17:18:58.782] [info] Loading persistent workspaces from Hyprland workspace rules
[2025-03-11 17:18:58.942] [info] Bar configured (width: 1920, height: 25) for output: HDMI-A-1
[2025-03-11 17:18:58.942] [error] Item '': No icon name or pixmap given.

• Step 3

Terminal 2

$ hyprctl keyword monitor "eDP-1, 1920x1080, -1920x0, 1"

Terminal 1

[2025-03-11 17:19:12.847] [info] Loading persistent workspaces from Hyprland workspace rules
[2025-03-11 17:19:12.973] [info] Bar configured (width: 1920, height: 25) for output: eDP-1
[2025-03-11 17:19:12.973] [error] Item '': No icon name or pixmap given.

• Step 4

Terminal 2

hyprctl keyword monitor "eDP-1, disable"

Terminal 1

** (waybar:16540): CRITICAL **: 17:46:05.034: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-03-11 17:46:05.034] [info] Hyprland IPC stopping...

** (waybar:16542): CRITICAL **: 17:46:05.039: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-03-11 17:46:05.040] [info] Hyprland IPC stopping...
[2025-03-11 17:46:05.044] [info] Bar removed from output: eDP-1

This is when the Hyprland modules start freezing. To recover, I have a script associated to a hotkey that restarts waybar.

Running on Arch with Waybar v0.12.0 and latest stable release of Hyprland.

Hope this helps in tracking down the bug!

[auroraveon]

it also happens to me when i have i have sigusr2 to waybar a few times to reload my theme qwq

[dybdeskarphet]

I'm having the same problem too. Other modules just work fine but hyprland module freezes after a display is plugged in or out.

[winkelnp]

Steps to reproduce:

1. A multi-monitor setup is needed. Start with one monitor disabled and without waybar running as a background process

2. Run "waybar" in a terminal window

3. In a new terminal window, enable the monitor via Hyprland command

4. Disable the monitor via Hyprland command

On my end it also occurs if the monitor is already running and is only disabled while waybar is running, i.e.:

1. A multi-monitor setup is needed, start with normal configuration and without waybar as background process
2. run "waybar" in a terminal window
3. Disable one of the monitors via Hyprland command

This gives the following output:

** (waybar:916248): CRITICAL **: 12:35:02.150: static void Glib::DispatchNotifier::unreference_instance(Glib::DispatchNotifier*, const Glib::Dispatcher*): assertion 'instance == notifier' failed
[2025-04-12 12:35:02.150] [info] Hyprland IPC stopping...
[2025-04-12 12:35:02.151] [info] Bar removed from output: eDP-1

Adding a monitor does not seem to cause this, only removing (whether or not that monitor was already enabled when waybar starts)

[dybdeskarphet]

Hey, here is a quick fix for you guys until this issue is solved:

#!/bin/bash

waybar &

handle() {
  case "$1" in
  monitoraddedv2* | monitorremovedv2*)
    killall waybar
    sleep 0.3
    waybar &
    ;;
  esac
}

socat -U - UNIX-CONNECT:$XDG_RUNTIME_DIR/hypr/$HYPRLAND_INSTANCE_SIGNATURE/.socket2.sock | while read -r line; do handle "$line"; done

Start this script instead of using the waybar command and it will restart the bar when a display is plugged in/out. And because it uses the socket directly, there is no polling.

[lfos]

Looks like this may be a regression caused by #3945, hopefully the original PR author has sufficient context to take a look and come up with a quick fix.

[zjeffer]

I'll have a look soon, thanks for the ping.

I've been having the same issue for a while (I have a keybind to restart waybar similar to @dybdeskarphet's solution) , wasn't aware that it's my PR that might be causing this 😆

[zjeffer]

Reading the thread more thoroughly now, it's not the same issue I was experiencing. In my case, disconnecting my laptop from my docking station (which has 2 monitors connected) sometimes crashes waybar, but it's quite rare.

I tried to reproduce this issue using @123Daktary and @winkelnp's steps but couldn't reproduce it. Can someone turn on trace logging (--log-level trace) when starting waybar, and post the trace logs after reproducing it? Also include your Hyprland and Waybar versions, and how often you can reproduce it (every time, only once in x times, etc). Thanks.

I'll have another look at the IPC code in the meantime.

[lfos]

I tried to reproduce this issue using @123Daktary and @winkelnp's steps but couldn't reproduce it. Can someone turn on trace logging (--log-level trace) when starting waybar, and post the trace logs after reproducing it? Also include your Hyprland and Waybar versions, and how often you can reproduce it (every time, only once in x times, etc). Thanks.

Thanks for taking a look!

I followed these steps:

1. Have the following bindings in my hyprland config to automatically enable/disable the laptop monitor when I open/close the lid:

   bindl = , switch:on:Lid Switch, exec, hyprctl keyword monitor "eDP-1,disable"
   bindl = , switch:off:Lid Switch, exec, hyprctl keyword monitor "eDP-1,3072x1920@120.00Hz,0x0,1.5"
   

2. Run hyprland and waybar on external monitor. Switch workspaces - all good.
3. Open laptop lid; brings up the additional laptop monitor. Switch workspaces - all good.
4. Close laptop lid again; disables the additional laptop monitor. Switch workspaces - active workspace doesn't seem to get updated on waybar anymore.

Trace log excerpt: https://gist.githubusercontent.com/lfos/529fa170344e39eab7e1dd620edf608d/raw

Let me know if you need anything else!