FetchContent_Declare(
    eigen
    GIT_REPOSITORY https://gitlab.com/libeigen/eigen.git
    GIT_TAG 3.4
    GIT_PROGRESS TRUE
)
set(EIGEN_BUILD_DOC OFF CACHE INTERNAL "")
set(BUILD_TESTING OFF CACHE INTERNAL "")
set(EIGEN_BUILD_PKGCONFIG OFF CACHE INTERNAL "")
FetchContent_MakeAvailable(eigen)