[CMake] target_compile_features no known features for CXX compiler for clang 9.0

[Rick Mann]

Trying to build Ceres, I'm running into an issue in which CMake 3.11.0-rc3 doesn't seem to recognize the clang that comes with the latest Xcode (Version 9.2 (9C40b)). Googling turns up similar, but old results, that seem to suggest one needs to update CMake. But -rc4 is the only more recent version, and its release notes don't say anything about this.

CMake Error at cmake/AddCeresCXX11RequirementsToTarget.cmake:70 (target_compile_features):
  target_compile_features no known features for CXX compiler

  "Clang"

  version 9.0.0.9000039.


Any suggestions? Thanks.


-- 
Rick Mann