cmake_minimum_required(VERSION 3.15) include(FetchContent) FetchContent_Declare( Eigen URL https://gitlab.com/libeigen/eigen/-/archive/3.4.0/eigen-3.4.0.tar.gz URL_HASH MD5=4c527a9171d71a72a9d4186e65bea559) FetchContent_MakeAvailable(Eigen)