When Cross Compiling for Android with the NDK, this variable provides the NDK’s “host tag” used to construct the path to prebuilt toolchains that run on the host.
© 2000–2017 Kitware, Inc. and Contributors
Licensed under the BSD 3-clause License.
https://cmake.org/cmake/help/v3.9/variable/CMAKE_ANDROID_NDK_TOOLCHAIN_HOST_TAG.html