LDFLAGS: -L/usr/local/opt/qt5/lib
CPPFLAGS: -I/usr/local/opt/qt5/include
brew linkapps qt5
$ brew install qt5
$ ls /usr/local/opt/qt5/lib/cmake/Qt5Widgets/Qt5WidgetsConfig.cmake
$ /usr/local/opt/qt5/lib/cmake/Qt5Widgets/Qt5WidgetsConfig.cmake
$ export CMAKE_PREFIX_PATH=/usr/local/opt/qt5/
$ cd ./build
$ cmake ../CMakeLists.txt
$ make -j8
Acroding to http://www.cmake.org/cmake/help/v3.0/variable/CMAKE_PREFIX_PATH.html, the cmake function FIND_LIBRARY() will appends /lib to each of the directories. So done.