To build
cp src/gcconfig.pri.in src/gcconfig.pri
cp qwt/qwtconfig.pri.in qwt/qwtconfig.pri
Edit both src/gcconfig.pri and qwt/qwtconfig.pri as necessary, then
qmake
make
To uninstall the older FTDI VCP drivers on Mac OS X, open a Terminal and type:
sudo mv /System/Library/Extensions/FTDIUSBSerialDriver.kext /tmp
Type your password when prompted, then restart your computer.