CMake: Absolute lib-pathnames given to target_link_library( PRIVATE ) are exported, appear in generated INTERFACE_LINK_LIBRARIES. How do I?

In a large CMake/C++ project our major library target Foo is being added. It has many statically linked dependencies that are provided as absolute-paths to target_link_libraries(). Now I'm writing the CMake to export this library once built, including the generated CMake so a library consumer can simply use CMake find_package(). However the generated FooTargets.cmake is embeding the absolute-paths of the link-libraries instead of just the library names.

Additionally, I've already created an add_library(BarCommon INTERFACE), to wrap up the referenced 3rd-party static libs separately and that seems to be working and the client-application consumed it. That accounts for 90% of the libraries also mentioned by FOO. So really FOO's exported INTERFACE_LINK_LIBRARIES should be about 3 file names instead of 40 absolute-pathnames.

1. I'm confused, why is the target_link_libraries(FOO PRIVATE ${libs} is defining the exported 'INTERFACE_LINK_LIBRARIES' property?

2. I would like that generated INTERFACE_LINK_LIBRARIES property to be only library filenames, and optimally have finer control over which filenames end up in it. How do I control this?

Code:

Inside a large CMake Macro for generating targets we have this: -

• I call it to create library/target FOO.
• _TARGET_ARGS_LIB_DEPENDS will resolve to ABSOLUTE FILE PATHNAMES for about 40 statically linked library dependencies.

add_library(${TargetName} STATIC ${AllSources} ${_TARGET_ARGS_OBJ_FILES})

  <snip>

target_link_libraries(${TargetName}
    PRIVATE
        $<${GCC}:-Wl,--start-group>
        ${_TARGET_ARGS_LIB_DEPENDS}
        $<${GCC}:-Wl,--end-group>
    )

where that longish function returns I have just added these blocks:

target_link_directories(FOO
    INTERFACE
        $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>
        $<INSTALL_INTERFACE:foo/lib>
    )

target_include_directories(FOO
    INTERFACE
        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
        $<INSTALL_INTERFACE:foo/include>
    )

install(TARGETS Foo
    EXPORT
        FooTargets
    DESTINATION
        foo/lib
    )    

There is some more 'install' boilerplate at the end of my CMakeLists.txt After I run CMAKE, build the project and run the 'INSTALL' target CMake generated from Visual Studio I can examine generated file: local_install\Release\Windows\Foo\lib\cmake\Foo\FooTargets.cmake shows:

set_target_properties(Nexidia.Workbench.StaticLib.StaticLib PROPERTIES
  INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/Foo/include"
  INTERFACE_LINK_DIRECTORIES "${_IMPORT_PREFIX}/Foo/lib"
  INTERFACE_LINK_LIBRARIES "\$<LINK_ONLY:\$<0:-Wl,--start-group>>;C:/full/path/to/libA.lib;C:/full/path/to/libB.lib \$<LINK_ONLY:\$<0:-Wl,--end-group>>"
)

(with the full paths to about 40 libraries).

PS. I'm reading Professional CMake: A Practical Guide, so if someone could cite the chapter/sub-section that answers this it might help.