release/mainwindow.o:mainwindow.cpp:(.text+0x3a5): undefined reference to `cv::face::createLBPHFaceRecognizer(int, int, int, int, double)'
collect2.exe: error: ld returned 1 exit status
Makefile.Release:81: recipe for target '..\FaceDemo\bin\FaceDemo.exe' failed
mingw32-make[1]: *** [..\FaceDemo\bin\FaceDemo.exe] Error 1
mingw32-make[1]: Leaving directory 'I:/D/work/FaceDemo/build-FaceDemo-Desktop_Qt_5_4_1_MinGW_32bit-Release'
mingw32-make: *** [release] Error 2
makefile:34: recipe for target 'release' failed
11:33:13: 进程"D:\Qt\5.4.1\Tools\mingw491_32\bin\mingw32-make.exe"退出,退出代码 2 。
Error while building/deploying project FaceDemo (kit: Desktop Qt 5.4.1 MinGW 32bit)
When executing step "Make"