Hi -

I am compiling a shared library object and am using elements from Qwt for the UI. I am able to compile the code without errors or warnings (suggesting that the proper include files are found and linked against) however get an error when I attempt to load the shared object in my app. I receive the following error:

../src/plugin.cpp:50:Plugin::load : failed to load oscilloscope.so: /usr/local/lib/rtxi/oscilloscope.so: undefined symbol: _ZNK13QwtPlotCanvas10metaObjectEv

When I use c++filt, it simply tells me that QwtPlotCanvas::metaObject() const is the symbol it can not find.

I have tried every permutation possible to ensure that I am linking against the qwt library (-lqwt) and providing the path for it. The following shows my current flag for linking against libraries

QT_CXXFLAGS = -I/usr/include/qt4 -I/usr/include/qt4/QtCore/ -I/usr/include/qt4/QtGui/ -I/usr/include/qt4/QtXml/ -I/usr/local/lib/rtxi_includes/ -I/usr/local/lib/qwt/include/

QT_LIBS = -L/usr/lib/qt4/ -L/usr/local/lib/qwt/lib/ -DQT_QT3SUPPORT_LIB -DQT3_SUPPORT -DQT_XML_LIB -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -lQtGui -lQtCore -lQt3Support -lQtXml -lqwt

What am I missing? I don't understand where that error is coming from.

Any advice greatly appreciated.