Link error: undefined reference to `PythonQt::init(int, QByteArray const&)'

[David Lyon]

I downloaded PythonQt3.1 and opened src.pro with QtCreator4.2.2 (QT 5.8.0), everything complied and linked fine under Ubuntu 16.04 (after commenting out the two hint buttons), I ended up with eight *.so files:
libPythonQt.so - 20 bytes
libPythonQt.so.1 - 20 bytes
libPythonQt.so.1.0 - 20 bytes
libPythonQt.so.1.0.0 - 3.4 MBytes
and their debug counterparts in /home/user/Downloads/PythonQt3.1/lib/

I created a simple program in QtCreator to test in /home/user/CppCode/StocksWeb/ with this pro file:

QT       += core gui sql widgets
INCLUDEPATH += "/home/user/Downloads/PythonQt3.1/src"
INCLUDEPATH += "/usr/include/python2.7"
Debug:LIBS += -L"/home/user/Downloads/PythonQt3.1/lib" -libPythonQt_d.so
Release:LIBS += -L"/home/user/Downloads/PythonQt3.1/lib" -libPythonQt.so
DEFINES += QT_DEPRECATED_WARNINGS
SOURCES += src/main.cpp src/mainwindow.cpp
HEADERS  += src/mainwindow.h
FORMS    += src/mainwindow.ui

And this main code (after reducing it greatly):

#include "mainwindow.h"
#include <QApplication>
#include <PythonQt.h>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
// Tried both
//    PythonQt::init(1, QByteArray("PythonQt"));
    PythonQt::init();

    return a.exec();
}

The two cpp and ui files compile fine, however when linking I get this output in QtCreater:

main.o: In function `main':
/home/user/CppCode/StocksWeb/64debug/../src/main.cpp:11: undefined reference to `PythonQt::init(int, QByteArray const&)'
Makefile:237: recipe for target 'StocksWeb' failed
collect2: error: ld returned 1 exit status
make: *** [StocksWeb] Error 1
20:32:03: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project StocksWeb (kit: Desktop Qt 5.8.0 GCC 64bit)
When executing step "Make"
20:32:03: Elapsed time: 00:05.

After making no progress after serveral hours I decided to ask for help. Any hints or ideas would be greatly appreciated. Thanks!

                                        RESOLVED

---

I resolved it, I had to change the way the project file add paths to the libraries:

CONFIG(debug, debug|release): LIBS += -L$$PWD/../3rdParty/lib/ -lPythonQt_d
else: LIBS += -L$$PWD/../3rdParty/lib/ -lPythonQt

My normal path to 3rd party stuff is /home/user/CppCode/3rdParty/. Now everything appears to be right with the libraries and include files in the right place.

Just a reminder, once you have your libraries in a permenant place don't forget to run ldconfig to register them with the operating system.

[hanzongjin]

excuse me,I just want to know where you found PythonQt_d.lib. I haven't found it in the pythonQt3.1 zip package.