CMake Warning \(dev\) in CMP0082-NestedSub/CMakeLists\.txt:
  Policy CMP0082 is not set: Install rules from add_subdirectory\(\) are
  interleaved with those in caller\.  Run "cmake --help-policy CMP0082" for
  policy details\.  Use the cmake_policy command to set the policy and
  suppress this warning\.

This warning is for project developers\.  Use -Wno-dev to suppress it\.