CPack doesn't produce a debian dbgsym package alongside debian binary package

Hello all,

I have a CMake project which successfully builds a static library and packages it as a debian package. I would like to distribute a dgbsym package along with it. Altough I think I followed all the steps necessary, it still is not created.
Here is some info on dbgsym packages: https://wiki.ubuntu.com/Debug%20Symbol%20Packages

Would you mind giving my CMakeLists a quick look?
I tried these steps in CMake 3.13.4 and 3.16.3.

Unfortunately I have to post it inline, as, being a newly registered user, I cannot upload files yet.

    cmake_minimum_required(VERSION 3.13)

    #set( CMAKE_TOOLCHAIN_FILE       cmake/x86_64.gcc.toolchain.cmake )

    project( addition_lib
        DESCRIPTION     "Encrypts and decrypts some text"
        VERSION         1.0.0
        LANGUAGES       CXX )

    ####

    add_library( add )

    target_sources( add
        PRIVATE     add.cpp )

    target_include_directories( add
        PUBLIC      include )

    # Used for install() only
    set_target_properties ( add
        PROPERTIES
        PUBLIC_HEADER   "include/add.hpp" )

    install(
        TARGETS       add
        ARCHIVE       DESTINATION "lib"
        PUBLIC_HEADER DESTINATION "include" )

    ####

    message( STATUS "build type is " ${CMAKE_BUILD_TYPE} )

    set( CPACK_PACKAGE_NAME                ${PROJECT_NAME} )
    set( CPACK_PACKAGE_CONTACT             "Contact name" )
    set( CPACK_PACKAGE_VERSION             ${PROJECT_VERSION} )
    set( CPACK_PACKAGE_DESCRIPTION_SUMMARY "Description" )

    set( CPACK_GENERATOR                   DEB )
    set( CPACK_DEBIAN_PACKAGE_DEPENDS      "" )
    set( CPACK_DEB_COMPONENT_INSTALL       ON )
    set( CPACK_DEBIAN_DEBUGINFO_PACKAGE    ON )


    include( CPack )

CMake/CPack produces the following output:

manuel@debian:~/Documents/repos/dbgsym/build$ cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo .. && make package
    -- The CXX compiler identification is GNU 8.3.0
    -- Check for working CXX compiler: /usr/bin/c++
    -- Check for working CXX compiler: /usr/bin/c++ -- works
    -- Detecting CXX compiler ABI info
    -- Detecting CXX compiler ABI info - done
    -- Detecting CXX compile features
    -- Detecting CXX compile features - done
    -- build type is RelWithDebInfo
    -- Configuring done
    -- Generating done
    -- Build files have been written to: /home/manuel/Documents/repos/dbgsym/build
    Scanning dependencies of target add
    [ 50%] Building CXX object CMakeFiles/add.dir/add.cpp.o
    [100%] Linking CXX static library libadd.a
    [100%] Built target add
    Run CPack packaging tool...
    CPack: Create package using DEB
    CPack: Install projects
    CPack: - Run preinstall target for: addition_lib
    CPack: - Install project: addition_lib
    CPack: Create package
    -- CPACK_DEBIAN_PACKAGE_DEPENDS not set, the package will have no dependencies.
    CPack: - package: /home/manuel/Documents/repos/dbgsym/build/addition_lib-1.0.0-Linux.deb generated.

I checked completeness of the debian package with the following command:

    manuel@debian:~/Documents/repos/dbgsym/build$ ar xf addition_lib-1.0.0-Linux.deb && tar tf data.tar.gz
    ./usr/
    ./usr/include/
    ./usr/include/add.hpp
    ./usr/lib/
    ./usr/lib/libadd.a

I was told that I also need to specify COMPONENT when for the install clause, but then cpack crashes.

    install(
        TARGETS       add
        ARCHIVE       DESTINATION "lib"
        PUBLIC_HEADER DESTINATION "include"
        COMPONENT     dev )
    Run CPack packaging tool...
    CPack: Create package using DEB
    CPack: Install projects
    CPack: - Run preinstall target for: addition_lib
    CPack: - Install project: addition_lib
    CPack: -   Install component: Unspecified
    CPack: -   Install component: dev
    CPack: Create package
    -- CPACK_DEBIAN_PACKAGE_DEPENDS not set, the package will have no dependencies.
    terminate called after throwing an instance of 'std::logic_error'
      what():  basic_string::_M_construct null not valid
    make: *** [Makefile:98: package] Aborted

In case anyone would like to try this out, you can git-clone the repo I set up: https://gitlab.com/manuel_wagesreither/dbgsym-cpack