Cmake can't find qt when building vtk

Question

I am getting the following error while trying to build vtk with qt support:

 CMake Error at CMakeLists.txt:370 (MESSAGE):
   Qt 4.5.0 or greater not found.  Please check the QT_QMAKE_EXECUTABLE
   variable.

this is how I am running cmake:

mkdir vtk-build && cd vtk-build
cmake -DVTK_QT_VERSION:STRING=5 \
      -DQT_QMAKE_EXECUTABLE:PATH=/home/pendar/Qt/5.6/gcc_64/bin/qmake \
      -DVTK_Group_Qt:BOOL=ON \
      -DCMAKE_PREFIX_PATH:PATH=/home/pendar/Qt/5.6/gcc_64/lib/cmake  \
      -DBUILD_SHARED_LIBS:BOOL=ON \
      ../VTK

I also tried setting these settings to on:

  VTK_USE_QT:BOOL=ON \
  VTK_USE_GUISUPPORT:BOOL=ON \
  BUILD_SHARED_LIBS:BOOL=ON \
  VTK_USE_RENDERING:BOOL=ON \

which didn't work.

I'm using qt 5.6 and vtk 5.8.