How to clone and integrate external (from git) cmake project into local one
I would go with the first approach. You don't need to specify a build command because cmake is used by default. This could look like:
cmake_minimum_required(VERSION 3.0)project(GTestProject)include(ExternalProject)set(EXTERNAL_INSTALL_LOCATION ${CMAKE_BINARY_DIR}/external)ExternalProject_Add(googletest GIT_REPOSITORY https://github.com/google/googletest CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${EXTERNAL_INSTALL_LOCATION})include_directories(${EXTERNAL_INSTALL_LOCATION}/include)link_directories(${EXTERNAL_INSTALL_LOCATION}/lib)add_executable(FirstTest main.cpp)add_dependencies(FirstTest googletest)target_link_libraries(FirstTest gtest gtest_main pthread)I don't know if this is the correct/preferred way if there even is one. If you wanted to implement your second approach you would have to download the code with execute_process first.