forward declaration of 'struct QextSerialPortPrivate' Invalid arguments 'Candidates are: void addDestination(QsLogging::Destination *) Invalid arguments 'Candidates are: void addDestination(QsLogging::Destination *) invalid use of incomplete type 'struct QextSerialPortPrivate' make: *** [debug] Error 2 make[1]: *** [debug/moc_qextserialport.o] make[1]: Target `first' not remade because of errors. ... .. .