Problems when adding serialport module in Qt project

[aha_1980]

@douglas you are tryin to compile a new QSerialPort against an older Qt.

Add a git checkout -b v5.7.1 directly after the git clone command and rebuild.

[douglas]

@aha_1980 I add "git checkout -b v5.7.1" , but the qdeadlinetimer.h error shown above still remains during the make procedure. Any hints?

[jsulm]

@douglas Did you try to delete the build folder, create new one and to start from there?

[douglas]

@jsulm Yes, I did. I always obtain the

fatal error: qdeadlinetimer.h: File o directory non esistente
compilation terminated.

[aha_1980]

@douglas please send the output of git status

[douglas]

@aha_1980

Sul branch v5.7.1
Untracked files:
  (use "git add <file>..." to include in what will be committed)

	./

nothing added to commit but untracked files present (use "git add" to track)

Am I missing something?

[aha_1980]

@douglas Looks good so far.

But let's move slowly. I re-read you post from 5 hours ago:

@aha_1980 Thanks. In Qt Creator I set Qt 5.7.1 in the "Qt Version" for the selected kit for my project. Now I can add the serialport module in my .pro file and build the app

If you can build the app, then you already have the serialport module!

but when I try to run it on my target device, the application does not start and the following error appears:

But you don't have the libraries on your target device.

[douglas]

@aha_1980 Thanks, I understand. In order to obtain those libraries on my target device is something that I should copy from my host PC onto the device itself or I should install directly on the device side in any way?

[aha_1980]

@douglas In the most easy and hacky way, just copy the needed *.so files to the other Qt *.so files on your device.

Depending on your cross toolchain, there may be a more clean way (like building a new image), but that - as said - depends on you toolchain.

[Pablo J. Rogina]

@douglas as @aha_1980 said, maybe easiest way is to copy the serialport module *.so the same way you're deploying the file(s) for your application. Perhaps at the beginning it's easy to copy the shared library into same folder as application's executable

[douglas]

@Pablo-J.-Rogina , @aha_1980 thank you. I expected to find the libQt5SerialPort.so.5 (the missing library) inside the qtserialport folder generated after the steps:

$ git clone git://code.qt.io/qt/qtserialport.git
$ mkdir qtserialport-build
$ cd qtserialport-build
$ qmake ../qtserialport/qtserialport.pro

but I couldn't find it. I searched into my host PC for that file, I found few results, but they are located into the Qt installation folder, they are not cross-compiled for my needs, I think.
When exactly that library should be created, or where it should be located?
Thanks!

[jsulm]

@douglas Are you sure you're cross compiling your app?
If so just do

ldd YOUR_APP_EXE

it will show you which libs it is linked against, you then will know where the serial port lib is.

[douglas]

@jsulm the ldd command does not give any result; it gives a message saying it is "not a dynamic exacutable"..

[douglas]

Solved. The missing libQt5SerialPort.so.5 error on the target device was because that library effectively was not present. On the host side I added that library in the package list of the image and rebuild the image itself.