Project ERROR: Unknown module(s) in QT: designer

Hiloshi

Dear Sirs,

I am facing the same issue. I also stop at Project ERROR: Unknown module(s) in QT: designer

My procedure is:

Use QT creator open qwt.pro
select Desktop QT5.8.0 GCC 64bit to build project
result is OK.(no error)
switch to "Raspberry Pi" then build project. (/rpi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/arm-linux-gnueabihf-g++)
result is " Unknown module(s) in QT: designer"

According to this discussion: http://www.qtcentre.org/threads/59011-Error-building-qwt-6-1-0-with-qmake-3-0
It same as @SGaist 's suggestion, it needs to compiler qwt.pro twice(if using cross-compiler).
Do I have to comment out designer for the fourth step (the 2nd compiler) ?
How to do it ? Does it means QT+=designer in qwt.pro (manual add for step2) or the

QWT_INSTALL_PLUGINS   = $${QWT_INSTALL_PREFIX}/plugins/designer

in qwtconfig.pri ??

Is there anyone have similar experience ?

Thanks for any help.

SGaist

IIRC, you need to disable the QWT_CONFIG += QwtDesigner line in qwtconfig.pri.

Hiloshi

Dear @SGaist ,

Yes, your suggestion is correct. After comment out

QWT_CONFIG += QwtDesigner

I can use rpi(/arm-linux-gnueabihf-g++) compiler the qwt project without error.

Though I still don't know how to add qwt into designer correctly, this may belong to different topic. I will arrange my test procedure and create different topic.

Thanks.

SGaist

The plugin for Designer must be built with the same version of Qt than Designer/Creator was built with (on Windows this includes compiler version).

That's why it's recommended to split the plugin project in two:

One is a library with all the widget(s)
One is the plugin itself

The plugin will be used to design your widget while the library will be used to link the application thus when you cross-compile you only need the library for the target.

Hiloshi

I installed QT Creator into the ubuntu 16.04,

After first compiler by linux-g++, libqwt_designer_plugin.so was created.
and then I open terminal and run "sudo make install" in /build-qwt-Desktop_Qt_5_8_0_GCC_64bit-Debug/. Then I can see qwt-6.1.3 folder was generated to /usr/local

then as @SGaist said, I comment out qwtdesigner, then run 2nd compiler.
2nd compiler is linux-rasp-pi-g++, then generate ../build-qwt-Raspberry_Pi-Debug.

Where should I copy libqwt_designer_plugin.so to ??
I expect after this process, I should able to see qwt widget in designer, right ?
I had tried copy to ~/Qt5.8.0/5.8/gcc_64/plugins/designer , but not working.
Should I do sudo make install in the ../build-qwt-Raspberry_Pi-Debug after 2nd compiler ?
After 2nd compiler, I think I should copy all ../build-qwt-Raspberry_Pi-Debug/lib to some place, but where ?? Replace everything in the /usr/local/qwt-6.1.3/lib ??

Appreciate for any help~

SGaist

The plugin should go within the installation of Qt Creator

You should have your cross-compiled Qwt in it's own folder.

Hiloshi

Dear Sirs,

I want to make qwt widget show on designer first, so I copy libqwt_designer_plugin.so to below foler, one by one.

/Qt5.8.0/5.8/gcc_64/plugins/designer
/Qt5.8.0/Tools/QtCreator/lib/qtcreator/plugins
/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/designer
/Qt5.8.0/Tools/QtCreator/lib/qtcreator/plugins/qbs/plugins
/Qt5.8.0/Tools/QtCreator/bin/designer <--manual create bin/designer folder
/usr/local/qwt-6.1.3/plugins/designer <--manual create plugins/designer folder

Unfortunately, none of them work... Any idea ?

PS. I re-open Qt Creator after copy to the folder each time.

SGaist

Did you check that you are using the same version of Qt that was used to build Qt Creator ?

Hiloshi

Dear @SGaist ,

I think they are the same, when I install qt creator I just download *.run file to complete the installation, so I think it use default make to build qt creator. Default gcc version is:
x86_64-linux-gnu

When compiler qwt desktop(ubuntu) version, I didn't export different compiler. So Qwt and qt creator should use the same make and gcc version.

Is there any point I can check ?

SGaist

You can start Qt Creator on the command line after setting the QT_DEBUG_PLUGINS environment variable to 1 so you can see what is happening with your plugin.

Hiloshi

Dear @SGaist ,

I reinstall QT Creator and copy libqwt_designer_plugin.so to
~/Qt5.8.0/Tools/QtCreator/lib/Qt/plugins/designer/, then I can see qwt widget in the designer.

I have not complete the whole process, but this is a good start. Thanks.

SGaist

What do you mean by "all process" ?

Hiloshi

Dear @SGaist ,

I can run on Ubuntu. Then I rebuild by Raspberry and did:

sudo make install

then copy lib to

~/Qt5.8.0/Tools/QtCreator/lib/Qt/lib/ 
~/Qt5.8.0/5.8/gcc_64/lib/

then build Qwt example OK, but when I run it, it show:

error while loading shared libraries: libqwt.so.6

So I think I didn't complete all process~

Hiloshi

Dear All,

After surf the Internet, it can be solved easily by
https://stackoverflow.com/questions/5375523/how-to-set-qwt-path-or-environment-variable?rq=1

Just copy *.so to RPi then add path to /etc/ld.so.conf

Thanks everyone.