I understand Eigen3 does create standard cmake variables, and thus does not work well with ament_target_dependencies. But is there anything wrong with target_link_libraries(my_target Eigen3::Eigen)?

According to the documentation, we can write this for ament_auto based packages:

• package.xml

<depend>eigen</depend>

• CMakeLists.txt

find_package(Eigen3 REQUIRED)
ament_auto_add_library(my_target 
  # ...
)
target_link_libraries(my_target Eigen3::Eigen)

VS using eigen3_cmake_module:

• package.xml

<depend>eigen3_cmake_module</depend>
<depend>eigen</depend>

find_package(Eigen3 REQUIRED)
ament_auto_add_library(my_target 
  # ...
)
ament_target_dependencies(my_target Eigen3)

Is there any difference between the two? Or is there a chance that with eigen3_cmake_module, it would be possible to skip the find_package and ament_target_dependencies thanks to ament_auto macros?

README mentions defect, but shows no traceability towards letting upstream know, nor does it give users of this package a way to know if/when they can stop using it depending on their Eigen version.

\cc @IanTheEngineer @sloretz