Running Qt application on headless Rpi
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I have followed the instructions listed here: http://www.ics.com/blog/building-qt-5-raspberry-pi to install qt on my rpi. Everything worked fine with the compilation.
I then tried to run the example program raspberrytest listed at the end of the blog, but I received the following error on my rpi:
QML debugging is enabled. Only use this in a safe environment.
QSocketNotifier: Can only be used with threads started with QThread
EGLFS: Unable to query physical screen size, defaulting to 100 dpi.
EGLFS: To override, set QT_QPA_EGLFS_PHYSICAL_WIDTH and QT_QPA_EGLFS_PHYSICAL_HEIGHT (in millimeters).I am not sure if this error is because I have no native display for my rpi and that it's running headless via VNC. I tried running a simple hello world console application and it generated the correct output.
Any clues?
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raspberrytest is a GUI application, that's probably the reason for the messages you see. It should work if you start the X server.
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raspberrytest is a GUI application, that's probably the reason for the messages you see. It should work if you start the X server.
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@jsulm I'm using VNC to log into the rpi and then running from the console window. Isn't that sufficient.
@Gagan-Mahan Actually these messages do not sound like errors, more like warnings. What is not clear from your original post: what happens after these messages are printed? Does the application terminate?
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@Gagan-Mahan Actually these messages do not sound like errors, more like warnings. What is not clear from your original post: what happens after these messages are printed? Does the application terminate?
@jsulm I don't see an output. It just stays at the command prompt. I guess I should be seeing a green screen. I installed a touch screen, but now I get the following error:
./raspberrytest: error while loading shared libraries: libGLESv2.so: cannot open shared object file: No such file or directory
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You need the libGLESv2.so lib. On Ubuntu/Debian you can find out which package provides it using apt-file.
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You need the libGLESv2.so lib. On Ubuntu/Debian you can find out which package provides it using apt-file.
@jsulm Thanks for your help on this so far. I installed the package, but now i've run into another problem, when I run the application I get the following error:
**QML debugging is enabled. Only use this in a safe environment.
This application failed to start because it could not find or load the Qt platform plugin "eglfs".Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen.
Reinstalling the application may fix this problem.
Aborted**Using -platform eglfs didn't help.
Here is a part output from my configure operation
QPA backends:
DirectFB ............. no
EGLFS ................ yes
KMS .................. no
LinuxFB .............. yes
XCB .................. noDo I need to rebuild Qt? Not sure what I need to fix though. Thanks!
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Search in the Qt forums, there are discussions about not found platform plugins. Your application is not able to find needed platform plugin. You should read http://doc.qt.io/qt-5/deployment.html as well.
