Empty content in popup/info windows using Wayland (Forcing X11 backend cause Eclipse IDE to hang)

[barrenaedu]

Describe the bug
Eclipse IDE in Wayland produces empty popup info windows. Forcing X11 backend using variable 'GDK_BACKEND=x11' shows popup info windows correctly, however this causes Eclipse to hang after a while when alternating between windows apps (for instance, using alt+tab).

To Reproduce
Run eclipse, open a java class, move/place the mouse cursor over a Java Class/method in the code and wait a second until the popup info window automatically appears. (See screenshots)

In the moment the empty window appears I can see in the terminal these Gtk-CRITICAL and Gtk-WARNING messages:

user@pc > ./eclipse
Aug 24, 2026 6:12:33 PM org.apache.aries.spifly.BaseActivator log
INFO: Registered provider ch.qos.logback.classic.spi.LogbackServiceProvider of service org.slf4j.spi.SLF4JServiceProvider in bundle ch.qos.logback.classic
18:12:36.038 [Start Level: Equinox Container: 9f213c99-bc2b-4c54-96e9-2ddeb9f81a89] DEBUG org.eclipse.jgit.internal.util.ShutdownHook -- register org.eclipse.jgit.util.FS$FileStoreAttributes$$Lambda/0x00007fa274225500@62f798b3 with shutdown hook
18:12:36.038 [Start Level: Equinox Container: 9f213c99-bc2b-4c54-96e9-2ddeb9f81a89] DEBUG org.eclipse.jgit.internal.util.ShutdownHook -- register org.eclipse.jgit.util.FS$FileStoreAttributes$$Lambda/0x00007fa274225500@62f798b3 with shutdown hook

(Eclipse:427564): Gtk-CRITICAL **: 18:12:58.157: gtk_widget_get_preferred_width_for_height: assertion 'height >= 0' failed

(Eclipse:427564): Gtk-WARNING **: 18:12:58.157: gtk_widget_size_allocate(): attempt to allocate widget with width 226 and height -1

Expected behavior
The popup/info window should appear WITH content like in this image:

Screenshots
This is the empty popup/info window that is currently being displayed

Environment:

• • [] All OS
• • Windows
• • Linux
• • macOS

2. Additional OS info (e.g. OS version, Linux Desktop, etc)

Operating System: Fedora Linux 44 (Workstation Edition)
Kernel: Linux 6.19.10-300.fc44.x86_64
GNOME Version: GNOME Shell 50.0
Backend: Wayland

3. JRE/JDK version
   I'm using the default JRE/JDK used by installation in the eclipse.ini, no changes.

...
-vm
plugins/org.eclipse.justj.openjdk.hotspot.jre.full.linux.x86_64_21.0.11.v20260515-1531/jre/bin/java
...

Version since
The error is reproducible in:

• 'eclipse-java-2026-03-R-linux-gtk-x86_64'
• 'eclipse-java-2026-06-R-linux-gtk-x86_64'
• 'eclipse-SDK-4.41RC1-linux-gtk-x86_64'

Workaround (or) Additional context

• Forcing X11 backend using variable 'GDK_BACKEND=x11' shows popup info windows correctly, however this causes Eclipse to hangs after a while when alternating between windows apps (for instance, using alt+tab); In most cases -or at least for me- Eclipse hangs when I alternate windows between Eclipse and Chrome.
  user@pc > GDK_BACKEND=x11 WEBKIT_DISABLE_COMPOSITING_MODE=1 WEBKIT_DISABLE_DMABUF_RENDERER=1 ./eclipse

• Variables 'WEBKIT_DISABLE_COMPOSITING_MODE=1' and 'WEBKIT_DISABLE_DMABUF_RENDERER=1' used along with 'GDK_BACKEND=x11' do not avoid Eclipse from hanging.

• Changing themes (dark/light) in GNOME does not solve the issue of the empty popup/info window or prevent Eclipse IDE from hanging when 'GDK_BACKEND=x11' is used.

This is a screenshot of the Eclipse IDE window when it hangs

[barrenaedu]

Today I tried several commands, for instance:
user@pc > GDK_BACKEND=x11 SWT_GTK3=1 GDK_DISABLE=vulkan WEBKIT_DISABLE_DMABUF_RENDERER=1 WEBKIT_DMABUF_RENDERER_FORCE_SHM=1 WEBKIT_DISABLE_COMPOSITING_MODE=1 LIBGL_ALWAYS_SOFTWARE=1 __GL_THREADED_OPTIMIZATIONS=0 __GL_SYNC_TO_VBLANK=0 ./eclipse
Still no success. The IDE keeps crashing after switching between some app windows, and the main window becomes unresponsive.

[merks]

FYI, our GTK expert is on vacation this week...

[vogella]

Would be interesting to see where boxHeight < 0 is set.

If you are up for a bit of hacky testing, here is a zip with a patched class and a script to apply it in your Eclipse installation. It SHOULD save the old JAR but no guarantee, better try this out in a copy of your Eclipse installation. See README.md for usage.

swt-3539-diagnostic.zip

[barrenaedu]

Would be interesting to see where boxHeight < 0 is set.

If you are up for a bit of hacky testing, here is a zip with a patched class and a script to apply it in your Eclipse installation. It SHOULD save the old JAR but no guarantee, better try this out in a copy of your Eclipse installation. See README.md for usage.

swt-3539-diagnostic.zip

Sure, this is the ouput file.
user@pc > .//eclipse -clean 2>&1 | tee /tmp/swt-3539.log
swt-3539.log

[vogella]

Please also include:

• xrandr --listmonitors or the Displays panel: how many monitors, their resolution and arrangement
• the display scaling factor (100%, 125%, 150%, ...)
• whether the Eclipse window was maximized

[vogella]

swt-3539-diagnostic.zip

And try this new zip. It has more diagnostics in and prevents that weight and height is set below zero.

[barrenaedu]

swt-3539-diagnostic.zip

And try this new zip. It has more diagnostics in and prevents that weight and height is set below zero.

I run the test twice, I could not see any popup window in this case. I'm also including a xrandr.log file and additional information of my system.

user@pc ~> echo $XDG_SESSION_TYPE
wayland

user@pc ~> xrandr --listmonitors
Monitors: 3
 0: +*DP-3 5120/600x2880/340+5120+2498  DP-3
 1: +DP-1 5120/700x2880/400+0+2498  DP-1
 2: +HDMI-1 3456/700x6144/400+10240+0  HDMI-1

user@pc ~> gsettings get org.gnome.desktop.interface scaling-factor
uint32 0

user@pc ~> gsettings get org.gnome.desktop.interface text-scaling-factor
1.25

user@pc ~> gsettings get org.gnome.mutter experimental-features
@as []

user@pc ~> lspci | grep -Ei 'vga|3d|display'
07:00.0 VGA compatible controller [0300]: NVIDIA Corporation GA102 [GeForce RTX 3080 Lite Hash Rate] [10de:2216] (rev a1)
	Subsystem: CardExpert Technology Device [10b0:2216]
	Kernel driver in use: nvidia
	Kernel modules: nouveau, nvidia_drm, nvidia

 user@pc ~> inxi -G
Graphics:
  Device-1: NVIDIA GA102 [GeForce RTX 3080 Lite Hash Rate] driver: nvidia
    v: 595.84
  Device-2: Logitech Webcam C270 driver: snd-usb-audio,uvcvideo type: USB
  Display: wayland server: Xwayland v: 24.1.9 compositor: gnome-shell
    v: 50.0 driver: gpu: nv_platform,nvidia,nvidia-nvswitch resolution:
    1: 3840x2160~60Hz 2: 3840x2160~60Hz 3: 3840x2160~60Hz 4: 3840x2160
  API: OpenGL v: 4.6.0 vendor: nvidia v: 595.84 renderer: NVIDIA GeForce
    RTX 3080/PCIe/SSE2
  API: EGL Message: EGL data requires eglinfo. Check --recommends.
  Info: Tools: api: glxinfo gpu: nvidia-settings,nvidia-smi wl: wayland-info
    x11: xdriinfo, xdpyinfo, xprop, xrandr

xrandr.log

swt-3539.log

[vogella]

Thanks @barrenaedu I'm leaving now my computer, I will look at the log tomorrow in detail. From the stack it looks like org.eclipse.jface.text.AbstractInformationControl.setSize is doing something silly.

[vogella]

As a workaround, try single or dual monitor usage instead of 3.

[barrenaedu]

Oh, you gave me good information there =D
I found a workaround for the three monitors, it seems the cause is the elevation of my third monitor in the gnome settings.

This configuration does NOT work:

This configuration does work (Reducing a bit the height of the third monitor)

Thank you!