Per local project fix: manually copying definitions to your .pro file from /usr/share/qt4/mkspecs/features/extserialport.prf:
INCLUDEPATH += /usr/include/qt4/QtExtSerialPort LIBS += -l$$qextLibraryName(qextserialport) DEFINES += QEXTSERIALPORT_USING_SHARED
And change them to:
INCLUDEPATH += /usr/include/QtExtSerialPort LIBS += -l$$qextLibraryName(qextserialport) DEFINES += QEXTSERIALPORT_USING_SHARED
Per local project fix: manually copying definitions to your .pro file from /usr/share/qt4/mkspecs/features/extserialport.prf:
INCLUDEPATH += /usr/include/qt4/QtExtSerialPortName(qextserialport)USING_SHARED
LIBS += -l$$qextLibrary
DEFINES += QEXTSERIALPORT_
And change them to:
INCLUDEPATH += /usr/include/QtExtSerialPortName(qextserialport)USING_SHARED
LIBS += -l$$qextLibrary
DEFINES += QEXTSERIALPORT_