Could not find the Qt platform plugin "eglfs" in ""

SGaist

Hi,

Start it with the QT_DEBUG_PLUGINS environment variable set to 1 to see why exactly it fails to load the plugin.

kutluyigitturk

@SGaist I don't know exactly how to do this, can you describe?

SGaist

export QT_DEBUG_PLUGINS=1

Then call your application.

kutluyigitturk

@SGaist said in Could not find the Qt platform plugin "eglfs" in "":

export QT_DEBUG_PLUGINS=1

These are the output lines

QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qt5opi/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqlinuxfb.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqlinuxfb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "linuxfb"
        ]
    },
    "archreq": 0,
    "className": "QLinuxFbIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqminimal.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqminimal.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimal"
        ]
    },
    "archreq": 0,
    "className": "QMinimalIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqoffscreen.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqoffscreen.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "offscreen"
        ]
    },
    "archreq": 0,
    "className": "QOffscreenIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqvnc.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqvnc.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "vnc"
        ]
    },
    "archreq": 0,
    "className": "QVncIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("vnc")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqwebgl.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqwebgl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "webgl"
        ]
    },
    "archreq": 0,
    "className": "QWebGLIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("webgl")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqxcb.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqxcb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "xcb"
        ]
    },
    "archreq": 0,
    "className": "QXcbIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/home/opi/platforms" ...
qt.qpa.plugin: Could not find the Qt platform plugin "eglfs" in ""
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: linuxfb, minimal, offscreen, vnc, webgl, xcb.

Aborted

SGaist

Then the version of Qt you have currently installed on your target does not provide that plugin.

Did you deploy the one you use for cross-compiling your application ?

kutluyigitturk

@SGaist

I do not have qt installed on the Orange Pi that I intend to run.

I think our main goal is to transfer executable files of qt projects to Orange Pi and connect remotely via ssh and run projects on Orange Pi.

SGaist

How did you install Qt on the OrangePi ?

kutluyigitturk

@SGaist I did not install Qt on the Orange Pi. I installed it on my host computer.

SGaist

That path /usr/local/qt5opi/ suggests a non standard installation. Hence it would be good to know how it was installed.

In any case, you have a cross-compiled Qt version on your host, correct ? If so, you should deploy it on your device so your application can use it.

kutluyigitturk

@SGaist
What am I supposed to understand from this deployment process? How can I do the deploy process? By the way, I leave the youtube link I took as an example here, this is how I installed it.

https://youtu.be/TmtN3Rmx9Rk

If you watch the video, you will understand how I installed it. I'm a bit of a novice in these matters and solving this problem will add a lot to me.

SGaist

Do you want to run your application on EGLFS or X11 like the video shows how to do ?

kutluyigitturk

@SGaist It makes no difference to me, I don't know the difference between the two? Is there a performance difference between the two?

SGaist

The first one uses the hardware directly and does not provide windowing capabilities the other uses the Xorg server. Like most desktop installation (unless they run in Wayland).

kutluyigitturk

@SGaist The Project I've created aims to command GPIO pins. Which do you think would be better for me to do?

JKSH

@kutluyigitturk said in Could not find the Qt platform plugin "eglfs" in "":

The Project I've created aims to command GPIO pins. Which do you think would be better for me to do?

Does your project need a GUI?

Since you are driving GPIO pins and you are running the application via SSH, that suggests to me that you don't need either EGLFS or X11. If that's the case, make your project a Console application instead of a GUI application -- then you won't need any of these GUI plugins.

(see https://doc.qt.io/qtcreator/creator-project-creating.html and select "Qt Console Application" when you create a project)

However, to make it a Console application, you must remove all GUI-related code (including Qt Quick) from your project.

kutluyigitturk

@JKSH I aim to control the GPIO pins with the help of an interface. So "Qt Console Application" doesn't really solve my problem.

I attach the video link I was inspired by,
https://youtu.be/lh8lqtgzqYA

JKSH

@kutluyigitturk said in Could not find the Qt platform plugin "eglfs" in "":

I attach the video link I was inspired by,
https://youtu.be/lh8lqtgzqYA

Raspberry Pi is not Orange Pi.

Your Orange Pi has Qt installed in /usr/local/qt5opi/. How did it get there? Did you install it, or does it come with the Orange Pi?

If it comes with the Orange Pi, I suggest you ask the producers of Orange Pi for instructions on how to use their software distribution.

Alternatively, try to force it to use the xcb plugin instead of the eglfs plugin and see what happens. From SSH, call ./OrangeDemlQml -platform xcb

kutluyigitturk

@JKSH I am creating the folder named /qt5opi in the /usr/local directory. I create with this command, sudo mkdir /usr/local/qt5opi . You can see the same process when you open the 14th minute of the video.

When I execute this command ./OrangeDemoQml -platform xcb I get a very similar error.

./OrangeDemoQml -platform xcb is the error I get when I execute this command:

qt.qpa.xcb: could not connect to display 
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: linuxfb, minimal, offscreen, vnc, webgl, xcb.

Aborted

Errors I get after running export QT_DEBUG_PLUGINS=1

QFactoryLoader::QFactoryLoader() checking directory path "/usr/local/qt5opi/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqlinuxfb.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqlinuxfb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "linuxfb"
        ]
    },
    "archreq": 0,
    "className": "QLinuxFbIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqminimal.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqminimal.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimal"
        ]
    },
    "archreq": 0,
    "className": "QMinimalIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqoffscreen.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqoffscreen.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "offscreen"
        ]
    },
    "archreq": 0,
    "className": "QOffscreenIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqvnc.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqvnc.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "vnc"
        ]
    },
    "archreq": 0,
    "className": "QVncIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("vnc")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqwebgl.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqwebgl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "webgl"
        ]
    },
    "archreq": 0,
    "className": "QWebGLIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("webgl")
QFactoryLoader::QFactoryLoader() looking at "/usr/local/qt5opi/plugins/platforms/libqxcb.so"
Found metadata in lib /usr/local/qt5opi/plugins/platforms/libqxcb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "xcb"
        ]
    },
    "archreq": 0,
    "className": "QXcbIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/home/opi/platforms" ...
loaded library "/usr/local/qt5opi/plugins/platforms/libqxcb.so"
qt.qpa.xcb: could not connect to display 
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: linuxfb, minimal, offscreen, vnc, webgl, xcb.

Aborted

JKSH

@kutluyigitturk said in Could not find the Qt platform plugin "eglfs" in "":

You can see the same process when you open the 14th minute of the video.

? The video is less than 6 minutes long.

I am creating the folder named /qt5opi in the /usr/local directory. I create with this command, sudo mkdir /usr/local/qt5opi

OK, where do the .so files (like libQt5Core.so) come from?

When I execute this command ./OrangeDemoQml -platform xcb I get a very similar error.

The root cause is very different.

The "eglfs" plugin failed to load because the plugin does not exist.
The "xcb" plugin failed because your X Server could not connect to your display: "qt.qpa.xcb: could not connect to display "

Do you have a display attached to your device? Have you logged into the display with the same Pi account that you used with SSH?

kutluyigitturk

@JKSH Sorry, here is the video I was talking about. https://youtu.be/TmtN3Rmx9Rk

I don't know where it came from, I think you can understand it if you examine the youtube link I gave above.
I'm very new to this stuff, please excuse my ignorance.

Yes, Orange Pi is connected to a monitor via HDMI cable. Should I try unplugging the HDMI cable?