Modules/Platform/GNU-Initialize.cmake - third_party/github.com/Kitware/CMake - Git at Google

 set(UNIX 1)

 set(CMAKE_LIBRARY_ARCHITECTURE_REGEX "[a-z0-9_]+(-[a-z0-9_]+)?-gnu[a-z0-9_]*")
	set(UNIX 1)

	set(CMAKE_LIBRARY_ARCHITECTURE_REGEX "[a-z0-9_]+(-[a-z0-9_]+)?-gnu[a-z0-9_]*")