cd src/ && make -f Makefile
make[1]: Entering directory `/home/saman/5.0.1/serialPortSrc/qtserialport/src'
cd serialport/ && make -f Makefile
make[2]: Entering directory `/home/saman/5.0.1/serialPortSrc/qtserialport/src/serialport'
make[2]: Nothing to be done for `first'.
make[2]: Leaving directory `/home/saman/5.0.1/serialPortSrc/qtserialport/src/serialport'
make[1]: Leaving directory `/home/saman/5.0.1/serialPortSrc/qtserialport/src'
cd examples/ && make -f Makefile
make[1]: Entering directory `/home/saman/5.0.1/serialPortSrc/qtserialport/examples'
cd cenumerator/ && make -f Makefile
make[2]: Entering directory `/home/saman/5.0.1/serialPortSrc/qtserialport/examples/cenumerator'
g++ -Wl,-O1 -o cenumerator main.o    -L/usr/lib/i386-linux-gnu -lQtGui -lQtCore -lpthread
main.o: In function `QList<QSerialPortInfo>::free(QListData::Data*) [clone .isra.1]':
main.cpp:(.text+0x47): undefined reference to `QSerialPortInfo::~QSerialPortInfo()'
main.o: In function `QList<QSerialPortInfo>::detach_helper(int)':
main.cpp:(.text._ZN5QListI15QSerialPortInfoE13detach_helperEi[QList<QSerialPortInfo>::detach_helper(int)]+0x68): undefined reference to `QSerialPortInfo::QSerialPortInfo(QSerialPortInfo const&)'
main.cpp:(.text._ZN5QListI15QSerialPortInfoE13detach_helperEi[QList<QSerialPortInfo>::detach_helper(int)]+0xc3): undefined reference to `QSerialPortInfo::~QSerialPortInfo()'
main.o: In function `main':
main.cpp:(.text.startup+0x5e): undefined reference to `QSerialPortInfo::availablePorts()'
main.cpp:(.text.startup+0x10f): undefined reference to `QSerialPortInfo::isBusy() const'
main.cpp:(.text.startup+0x16b): undefined reference to `QSerialPortInfo::hasProductIdentifier() const'
main.cpp:(.text.startup+0x1bb): undefined reference to `QSerialPortInfo::hasVendorIdentifier() const'
main.cpp:(.text.startup+0x212): undefined reference to `QSerialPortInfo::manufacturer() const'
main.cpp:(.text.startup+0x24a): undefined reference to `QSerialPortInfo::description() const'
main.cpp:(.text.startup+0x282): undefined reference to `QSerialPortInfo::systemLocation() const'
main.cpp:(.text.startup+0x2ba): undefined reference to `QSerialPortInfo::portName() const'
main.cpp:(.text.startup+0x644): undefined reference to `QSerialPortInfo::productIdentifier() const'
main.cpp:(.text.startup+0x674): undefined reference to `QSerialPortInfo::vendorIdentifier() const'
collect2: ld returned 1 exit status
make[2]: *** [cenumerator] Error 1
make[2]: Leaving directory `/home/saman/5.0.1/serialPortSrc/qtserialport/examples/cenumerator'
make[1]: *** [sub-cenumerator-make_default-ordered] Error 2
make[1]: Leaving directory `/home/saman/5.0.1/serialPortSrc/qtserialport/examples'
make: *** [sub-examples-make_default-ordered] Error 2

~/Qt5x.x.x/5.x.x/gcc_64/bin/qmake ~/yourqtprojectfolder/pilotnavigator/qtplayground-qtserialport/qtserialport.pro
make

sudo make install