Encountering QT_QPA_PLATFORM error when running code with Docker

Hello,

I encountered the following error when running your code inside Docker (error details below).
I have searched extensively online and tried all suggested solutions but none resolved the issue.

I have tried the following:
- Installed all missing OS dependencies
- ```sudo apt install libxcb-cursor0```
- ```sudo apt-get install '^libxcb.*-dev' libx11-xcb-dev libglu1-mesa-dev libxrender-dev libxi-dev libxkbcommon-dev libxkbcommon-x11-dev```
- ```sudo apt-get install libxcb-xinerama0```
- ...

- Set the environment variable `export QT_QPA_PLATFORM=offscreen`
- Checked `echo $DISPLAY`, which outputs `1` confirming the display environment variable is set correctly

However, the problem persists.

My system information is:

```bash
Linux fann 6.8.0-60-generic #63~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Apr 22 19:00:15 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
```

Could you please help me understand what might be causing this basic issue? Thank you!

```bash
root@docker-desktop:~/project_rss24_demo# ros2 launch as2_gazebo_assets launch_simulation.py simulation_config_file:=platforms_config/gazebo/world.yaml
[INFO] [launch]: All log files can be found below /root/.ros/log/2025-06-19-00-33-58-375506-docker-desktop-1566
[INFO] [launch]: Default logging verbosity is set to INFO

[INFO] [ruby $(which ign) gazebo-1]: process started with pid [1572]
[INFO] [monitor_sim-2]: process started with pid [1574]
[INFO] [create-3]: process started with pid [1576]
[INFO] [create-4]: process started with pid [1578]
[INFO] [create-5]: process started with pid [1581]
[INFO] [parameter_bridge-6]: process started with pid [1583]
[parameter_bridge-6] [INFO] [1750293239.105837571] [world.ros_gz_bridge]: Creating GZ->ROS Bridge: [/clock (ignition.msgs.Clock) -> /clock (rosgraph_msgs/msg/Clock)] (Lazy 0)
[create-5] [INFO] [1750293239.284182501] [ros_gz_sim]: Requested creation of entity.
[create-5] [INFO] [1750293239.284411500] [ros_gz_sim]: OK creation of entity.
[ruby $(which ign) gazebo-1] qt.qpa.xcb: could not connect to display :1
[ruby $(which ign) gazebo-1] qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
[ruby $(which ign) gazebo-1] This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
[ruby $(which ign) gazebo-1]
[ruby $(which ign) gazebo-1] Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.
[ruby $(which ign) gazebo-1]
[ruby $(which ign) gazebo-1] Stack trace (most recent call last):
[ruby $(which ign) gazebo-1] #31 Object "ign gazebo gui", at 0x55da54d8317e, in
[ruby $(which ign) gazebo-1] #30 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5eaa8e19, in ruby_run_node
[ruby $(which ign) gazebo-1] #29 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5eaa5317, in
[ruby $(which ign) gazebo-1] #28 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5ec3a30c, in rb_vm_exec
[ruby $(which ign) gazebo-1] #27 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5ec34c96, in
[ruby $(which ign) gazebo-1] #26 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5ec31fc5, in
[ruby $(which ign) gazebo-1] #25 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5ec2fc34, in
[ruby $(which ign) gazebo-1] #24 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5eb7ba4e, in
[ruby $(which ign) gazebo-1] #23 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5eaa69ac, in rb_protect
[ruby $(which ign) gazebo-1] #22 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5ec3ec61, in rb_yield
[ruby $(which ign) gazebo-1] #21 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5ec3a30c, in rb_vm_exec
[ruby $(which ign) gazebo-1] #20 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5ec34c96, in
[ruby $(which ign) gazebo-1] #19 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5ec31fc5, in
[ruby $(which ign) gazebo-1] #18 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5ec2fc34, in
[ruby $(which ign) gazebo-1] #17 Object "/usr/lib/x86_64-linux-gnu/ruby/3.0.0/fiddle.so", at 0x7f4a5ed8b44b, in
[ruby $(which ign) gazebo-1] #16 Object "/lib/x86_64-linux-gnu/libruby-3.0.so.3.0", at 0x7f4a5ebfd088, in rb_nogvl
[ruby $(which ign) gazebo-1] #15 Object "/usr/lib/x86_64-linux-gnu/ruby/3.0.0/fiddle.so", at 0x7f4a5ed8ad6b, in
[ruby $(which ign) gazebo-1] #14 Object "/lib/x86_64-linux-gnu/libffi.so.8", at 0x7f4a5ed7c492, in
[ruby $(which ign) gazebo-1] #13 Object "/lib/x86_64-linux-gnu/libffi.so.8", at 0x7f4a5ed7fe2d, in
[ruby $(which ign) gazebo-1] #12 Object "/usr/lib/x86_64-linux-gnu/libignition-gazebo6-ign.so.6.16.0", at 0x7f4a5e46dbcc, in runGui
[ruby $(which ign) gazebo-1] #11 Object "/lib/x86_64-linux-gnu/libignition-gazebo6-gui.so.6", at 0x7f4a59cf7a75, in ignition::gazebo::v6::gui::runGui(int&, char**, char const*, char const*, int, char const*)
[ruby $(which ign) gazebo-1] #10 Object "/lib/x86_64-linux-gnu/libignition-gazebo6-gui.so.6", at 0x7f4a59cf63a0, in ignition::gazebo::v6::gui::createGui(int&, char**, char const*, char const*, bool, char const*, int, char const*)
[ruby $(which ign) gazebo-1] #9 Object "/lib/x86_64-linux-gnu/libignition-gui6.so.6", at 0x7f4a5ad9b068, in ignition::gui::Application::Application(int&, char**, ignition::gui::WindowType)
[ruby $(which ign) gazebo-1] #8 Object "/lib/x86_64-linux-gnu/libQt5Widgets.so.5", at 0x7f4a57f71cec, in QApplicationPrivate::init()
[ruby $(which ign) gazebo-1] #7 Object "/lib/x86_64-linux-gnu/libQt5Gui.so.5", at 0x7f4a56b3bb6f, in QGuiApplicationPrivate::init()
[ruby $(which ign) gazebo-1] #6 Object "/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f4a588c0b16, in QCoreApplicationPrivate::init()
[ruby $(which ign) gazebo-1] #5 Object "/lib/x86_64-linux-gnu/libQt5Gui.so.5", at 0x7f4a56b38c07, in QGuiApplicationPrivate::createEventDispatcher()
[ruby $(which ign) gazebo-1] #4 Object "/lib/x86_64-linux-gnu/libQt5Gui.so.5", at 0x7f4a56b38712, in QGuiApplicationPrivate::createPlatformIntegration()
[ruby $(which ign) gazebo-1] #3 Object "/lib/x86_64-linux-gnu/libQt5Core.so.5", at 0x7f4a58690ba2, in QMessageLogger::fatal(char const*, ...) const
[ruby $(which ign) gazebo-1] #2 Object "/lib/x86_64-linux-gnu/libc.so.6", at 0x7f4a5e6287f2, in abort
[ruby $(which ign) gazebo-1] #1 Object "/lib/x86_64-linux-gnu/libc.so.6", at 0x7f4a5e642475, in raise
[ruby $(which ign) gazebo-1] #0 Object "/lib/x86_64-linux-gnu/libc.so.6", at 0x7f4a5e6969fc, in pthread_kill
[ruby $(which ign) gazebo-1] Aborted (Signal sent by tkill() 1647 0)
[create-3] [INFO] [1750293239.385086483] [ros_gz_sim]: Requested creation of entity.
[create-3] [INFO] [1750293239.385258035] [ros_gz_sim]: OK creation of entity.
[INFO] [create-5]: process has finished cleanly [pid 1581]
[INFO] [create-3]: process has finished cleanly [pid 1576]
[create-4] [INFO] [1750293239.547165841] [ros_gz_sim]: Requested creation of entity.
[create-4] [INFO] [1750293239.547445690] [ros_gz_sim]: OK creation of entity.
[INFO] [create-4]: process has finished cleanly [pid 1578]
[ruby $(which ign) gazebo-1] Escalating to SIGKILL on [Ignition Gazebo Server]
[INFO] [ruby $(which ign) gazebo-1]: process has finished cleanly [pid 1572]
[INFO] [launch]: process[ruby $(which ign) gazebo-1] was required: shutting down launched system
[INFO] [parameter_bridge-6]: sending signal 'SIGINT' to process[parameter_bridge-6]
[INFO] [monitor_sim-2]: sending signal 'SIGINT' to process[monitor_sim-2]
[parameter_bridge-6] [INFO] [1750293249.311238663] [rclcpp]: signal_handler(signum=2)
[monitor_sim-2] Traceback (most recent call last):
[monitor_sim-2] File "/root/aerostack2_ws/install/as2_gazebo_assets/share/as2_gazebo_assets/launch/monitor_sim.py", line 46, in
[monitor_sim-2] monitor_sim()
[monitor_sim-2] File "/root/aerostack2_ws/install/as2_gazebo_assets/share/as2_gazebo_assets/launch/monitor_sim.py", line 35, in monitor_sim
[monitor_sim-2] time.sleep(1)
[monitor_sim-2] KeyboardInterrupt
[ERROR] [monitor_sim-2]: process has died [pid 1574, exit code -2, cmd 'python3 /root/aerostack2_ws/install/as2_gazebo_assets/share/as2_gazebo_assets/launch/monitor_sim.py'].
[INFO] [parameter_bridge-6]: process has finished cleanly [pid 1583]

```