Project ERROR: Unknown module(s) in QT: serialport (Raspbian Jessie)

pbdot

I am trying to compile a Qt project that uses serialport module. I have installed the module using:

sudo apt-get install libqt5serialport5
sudo apt-get install libqt5serialport5-dev

The serialport is added in my .pro file:

QT += core gui network serialport

and the module is included in my header file:

#include < QtSerialPort/QSerialPort>

But when I compile, it says:

"Project ERROR: Unknown module(s) in QT: serialport"

Any idea what's wrong?

alt text

jsulm

@pbdot You installed libqt5serialport5 from the Linux distribution, but the qt in /usr/local/qt5 is for sure not the one from the distribution. Did you install qt5 by yourself in /usr/local/qt5? If so then you have to make sure libqt5serialport5 is installed there.

pbdot

Thanks @jsulm

Qt was installed through Raspbian package manager using:

sudo apt-get install qt5-qmake
sudo apt-get install libqt5

I can compile other project without issue, for example project using QNetwork which is included by default. Just not this one with QSerialPort.

How do I make sure libqt5serialport5 is there in /usr/local/qt5?

jsulm

@pbdot I'm not sure Raspbian is installing Qt in /usr/local/qt5, at least I wouldn't expect this. Are you sure /usr/local/qt5 is Qt from Raspbian you installed?
What does (in a terminal)

which qmake

say?

pbdot

Running which qmake returns the following:

pi@raspberrypi:~/SerialSend$ which qmake
/usr/bin/qmake
pi@raspberrypi:~/SerialSend$ qmake
qmake: could not exec '/usr/lib/arm-linux-gnueabihf/qt4/bin/qmake': No such file or directory

Hm. I think I made some mistake but I am a bit hazy now why I ended up with 2 qmake:

one in /usr/local/qt5 which is qt version 5
and another in /usr/bin/qmake which seems to be qt version 4 but somehow didn't work

pbdot

It seems that there are 2 qmake in the system:

/usr/bin/qmake : system seems to recognize this in the path
if I run it, it will complain "qmake: could not exec '/usr/lib/arm-linux-gnueabihf/qt4/bin/qmake': No such file or directory"
/usr/local/qt5/bin/qmake : system doesn't recognize it but it will run just fine if I specify full path like:
/usr/local/qt5/bin/qmake
make clean
make

I purged the old one by:

> sudo apt purge qt4*

After this, the system can recognize the qt5 qmake which is located at /usr/local/qt5

I then reinstalled serialport module:

> sudo apt-get install libqt5serialport5
> sudo apt-get install libqt5serialport5-dev

But now if run qmake, it complains:

qmake: could not find a Qt installation of ''

I checked my .bashrc file and at the end of the file, it has:

export LD_LIBRARY_PATH=/usr/local/qt5/lib/
export PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games:/usr/local/qt5/bin

pbdot

I am able to compile the project with serialport now after reinstalling qt5

> sudo apt-get install qt5-default

But I've got different error now which I think is a different issue altogether.

Unable to query physical screen size, defaulting to 100 dpi.

To override, set QT_QPA_EGLFS_PHYSICAL_WIDTH and QT_QPA_EGLFS_PHYSICAL_HEIGHT (in millimeters).
QOpenGLShaderProgram: could not create shader program
QOpenGLShader: could not create shader
Could not link shader program:
 ""
QOpenGLShaderProgram: could not create shader program
QOpenGLShader: could not create shader
QOpenGLShaderProgram::uniformLocation( texture ): shader program is not linked

IRBaboon

This one:

sudo apt-get install libqt5serialport5
sudo apt-get install libqt5serialport5-dev

Solved the Issue for me.