cmake report detected ninja version not fit requirement when command not found
if previously build dir already configured , but ninja executable is moved, cmake didn't report command not found ,but reports "The detected version of Ninja ("") is less than the version of Ninja required by CMake ("1.3") which is confused.
in cmGlobalNinjaGenerator.cxx:565 cmSystemTools::RunSingleCommand returns false , but there is no check on that.