Long path using ninja

Development
5

After re-running ninja, I get the same error:

-- Configuring done
CMake Warning in Modules/Loadable/VolumeRendering/SubjectHierarchyPlugins/CMakeLists.txt:
  The object file directory

    C:/Dev/Sn/Slicer-build/Modules/Loadable/VolumeRendering/SubjectHierarchyPlugins/CMakeFiles/qSlicerVolumeRenderingSubjectHierarchyPluginsPythonQt.dir/

  has 149 characters.  The maximum full path to an object file is 250
  characters (see CMAKE_OBJECT_PATH_MAX).  Object file

    generated_cpp/osm_qSlicerVolumeRenderingSubjectHierarchyPlugins/osm_qSlicerVolumeRenderingSubjectHierarchyPlugins_module_init.cpp.obj

  cannot be safely placed under this directory.  The build may not work
  correctly.


-- Generating done
-- Build files have been written to: C:/Dev/Sn/Slicer-build
[214/217] Performing build step for 'Slicer'
FAILED: Slicer-prefix/src/Slicer-stamp/Slicer-build
cmd.exe /C "cd /D C:\Dev\Sn\Slicer-build && "C:\Program Files\CMake\bin\cmake.exe" --build . && "C:\Program Files\CMake\bin\cmake.exe" -E touch C:/Dev/Sn/Slicer-prefix/src/Slicer-stamp/Slicer-build"
ninja: build stopped: subcommand failed.

C:\Dev\Sn>