How to add .so file to catkin workspace

edit

Environment ROS Noetic

I am trying to make an older package work in Noetic. I was able to compile rbdl library by:

$ git clone --recursive https://github.com/ORB-HD/rbdl-orb
$ mkdir rbdl-build
$ cd rbdl-build
$ cmake .. -DRBDL_BUILD_PYTHON_WRAPPER=ON -DCMAKE_INSTALL_PREFIX=~/catkin_ws/rbdl_ws/install -DRBDL_BUILD_ADDON_URDFREADER=ON -DRBDL_USE_ROS_URDF_LIBRARY=OFF -Wno-dev
$ make
$ make install

Now I create a new workspace:

$ mkdir -p talos_robot/src
$ cd talos_robot/src
$ catkin_init_workspace
$ cd ..
$ mkdir build
$ cd build
$ cmake ../src -DCMAKE_INSTALL_PREFIX=../install -DCATKIN_DEVEL_PREFIX=../devel
$ cd ..
$ cd src
$ git clone git clone https://github.com/pal-robotics/talos_robot.git
$ cd ..
$ make

Then I copied rbdl.so file into install folder

$ catkin_make install

But it's not picking it up, as I still get this error:

-- Could NOT find rbdl (missing: rbdl_DIR)
-- Could not find the required component 'rbdl'. The following CMake error indicates that you either need to install the package with the same name or change your environment so that it can be found.
CMake Error at /opt/ros/noetic/share/catkin/cmake/catkinConfig.cmake:83 (find_package):
  Could not find a package configuration file provided by "rbdl" with any of
  the following names:

    rbdlConfig.cmake
    rbdl-config.cmake

  Add the installation prefix of "rbdl" to CMAKE_PREFIX_PATH or set
  "rbdl_DIR" to a directory containing one of the above files.  If "rbdl"
  provides a separate development package or SDK, be sure it has been
  installed.
Call Stack (most recent call first):
  talos_robot/talos_description/test/CMakeLists.txt:2 (find_package)


-- Configuring incomplete, errors occurred!
See also "/home/osilva/talos_robot/build/CMakeFiles/CMakeOutput.log".
See also "/home/osilva/talos_robot/build/CMakeFiles/CMakeError.log".

Below my CMakeLists.txt file:

# toplevel CMakeLists.txt for a catkin workspace
# catkin/cmake/toplevel.cmake

cmake_minimum_required(VERSION 3.0.2)

project(Project)

set(CATKIN_TOPLEVEL TRUE)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)

# search for catkin within the workspace
set(_cmd "catkin_find_pkg" "catkin" "${CMAKE_SOURCE_DIR}")
execute_process(COMMAND ${_cmd}
  RESULT_VARIABLE _res
  OUTPUT_VARIABLE _out
  ERROR_VARIABLE _err
  OUTPUT_STRIP_TRAILING_WHITESPACE
  ERROR_STRIP_TRAILING_WHITESPACE
)
if(NOT _res EQUAL 0 AND NOT _res EQUAL 2)
  # searching fot catkin resulted in an error
  string(REPLACE ";" " " _cmd_str "${_cmd}")
  message(FATAL_ERROR "Search for 'catkin' in workspace failed (${_cmd_str}): ${_err}")
endif()

# include catkin from workspace or via find_package()
if(_res EQUAL 0)
  set(catkin_EXTRAS_DIR "${CMAKE_SOURCE_DIR}/${_out}/cmake")
  # include all.cmake without add_subdirectory to let it operate in same scope
  include(${catkin_EXTRAS_DIR}/all.cmake NO_POLICY_SCOPE)
  add_subdirectory("${_out}")

else()
  # use either CMAKE_PREFIX_PATH explicitly passed to CMake as a command line argument
  # or CMAKE_PREFIX_PATH from the environment
  if(NOT DEFINED CMAKE_PREFIX_PATH)
    if(NOT "$ENV{CMAKE_PREFIX_PATH}" STREQUAL "")
      if(NOT WIN32)
        string(REPLACE ":" ";" CMAKE_PREFIX_PATH $ENV{CMAKE_PREFIX_PATH})
      else()
        set(CMAKE_PREFIX_PATH $ENV{CMAKE_PREFIX_PATH})
      endif()
    endif()
  endif()

  # list of catkin workspaces
  set(catkin_search_path "")
  foreach(path ${CMAKE_PREFIX_PATH})
    if(EXISTS "${path}/.catkin")
      list(FIND catkin_search_path ${path} _index)
      if(_index EQUAL -1)
        list(APPEND catkin_search_path ${path})
      endif()
    endif()
  endforeach()

  # search for catkin in all workspaces
  set(CATKIN_TOPLEVEL_FIND_PACKAGE TRUE)
  find_package(catkin QUIET
    NO_POLICY_SCOPE
    PATHS ${catkin_search_path}
    NO_DEFAULT_PATH NO_CMAKE_FIND_ROOT_PATH)
  unset(CATKIN_TOPLEVEL_FIND_PACKAGE)

  if(NOT catkin_FOUND)
    message(FATAL_ERROR "find_package(catkin) failed. catkin was neither found in the workspace nor in the CMAKE_PREFIX_PATH. One reason may be that no ROS setup.sh was ...