Minimal CMake version
Looks like the required CMake version 3.6 in the main CMakeLists.txt is too low:
cmake_minimum_required(VERSION 3.6)
You're using add_library() call without specifying the source files. This feature was introduced in CMake 3.11.
doda 
Tera Term
Looks like the required CMake version 3.6 in the main CMakeLists.txt is too low:
cmake_minimum_required(VERSION 3.6)
You're using add_library() call without specifying the source files. This feature was introduced in CMake 3.11.