fatal error: QtConcurrent/QtConcurrent: No such file or directory

[yuyutangTW]

./bootstrap.sh
./configure
qmake gingr.pro
make

g++ -c -pipe -std=c++11 -include src/memcpyLink.h -D_GNU_SOURCE -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_XML_LIB -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/local/mkspecs/default -I. -I/usr/local/include/QtCore -I/usr/local/include/QtGui -I/usr/local/include/QtXml -I/usr/local/include -I. -Isrc -I/usr/local/include -I/usr/local/include -I. -o MainWindow.o src/MainWindow.cpp
src/MainWindow.cpp:20:37: fatal error: QtConcurrent/QtConcurrent: No such file or directory
compilation terminated.
Makefile:769: recipe for target 'MainWindow.o' failed
make: *** [MainWindow.o] Error 1

ubuntu 16.04

qmake -v
QMake version 2.01a
Using Qt version 4.8.5 in /usr/local//lib

where is my error ?
Thank you for your help

[barracuda156]

So what was the solution, if any?