QXcbConnection: Could not connect to display
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Hi all!
I am developing my QtQuick2 application on Ubuntu 16.04.
Now I am trying to remote debug my QtQuick2 application on an Ubuntu 15.04.
But this does not work.
I always get following message and then the application aborts:QXcbConnection: Could not connect to display Process killed by signal
Does anyone have an idea what could be the reason for this problem and how it can be solved?
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@m.sue :
Oh. I forgot to mention.
I am using the QtCreator and therefore I am connecting via ssh.
The connection it self can be established. But then my application crashes with the message: "QXcbConnection: Could not connect to display. Process killed by signal." -
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@m.sue :
I tried it with ssh -X from the Ubuntu 16 command line.
This is also not working.
It gives me the following error messages:Failed to create OpenGL context for format QSurfaceFormat(version 2.0, options QFlags<QSurfaceFormat::FormatOption>(), depthBufferSize 24, redBufferSize -1, greenBufferSize -1, blueBufferSize -1, alphaBufferSize -1, stencilBufferSize 8, samples -1, swapBehavior QSurfaceFormat::SwapBehavior(DoubleBuffer), swapInterval 1, profile QSurfaceFormat::OpenGLContextProfile(NoProfile))
Any idea about this?
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@m.sue :
I am not sure if I understand you right here.
For summerize:-
I can compile and debug the app directly on my Ubuntu 16.
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I can also compile remote debug the app on and Raspberry Pi.
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I have only problems with remote debugging on Ubuntu 15.
So the QtCreator is able to remote debug QML programs.
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Hi @MHermann
Yes but I think you have a problem to run a QML program on Ubuntu 15 remotely on Ubuntu 16. That is independent of QtCreator. The problem is to realize OpenGL commands generated in the program running on Ubuntu 15 on the graphics card of your Ubuntu 16 machine. This can be a configuration issue, a general problem, who knows.
-Michael.
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Hi @MHermann ,
I have the same problem. i tried to fix it by setting these evironment variables (DISPLAY, XAUTHORITY) but I still get this error:
qt.qpa.screen: QXcbConnection: Could not connect to display <VALUE>
Could not connect to any X display.
I did not set the values of the environment variables. How did you set the values? -
Hi,
Maybe that can help.Cross-compiling Qt-5.10 on Raspberry Pi 3 running Raspbian Stretch
In Qt Creator, the Run parameters for the device are:
Use System Environment and
Set DISPLAY to :0
Set XAUTHORITY to /home/pi/.XauthorityNote that I have also set the run argument as -platform xcb