Yarp: If YARP is configured with YCM, YCM modules are not present in the YARP_MODULE_PATH

[traversaro]

Describe the bug
If YARP is configured without YCM, CMake modules like FindACE.cmake are installed and are present in the YARP_MODULE_PATH variable (see https://github.com/robotology/yarp/blob/devel/cmake/template/YARPConfig.cmake.in#L119 and https://github.com/robotology/yarp/blob/devel/cmake/template/YARPConfig.cmake.in#L264).
If instead YARP is configured with YCM, this files are installed by YCM and so they are not available in the YARP_MODULE_PATH .

To Reproduce
Configure YARP devel using YCM, with ICUB devel, and enable the option ENABLE_icubmod_embObjMotionControl (this is just a random device that uses ACE).

Expected behavior
That the behaviour of YARP configured with YCM and YARP configured without YCM is consistent, for example my adding YCM_MODULE_PATH to YARP_MODULE_PATH in the YARPConfig.cmake file.

[traversaro]

cc @claudiofantacci

[claudiofantacci]

I just want to report that you can enable any option, even the basic one (cartesian and gaze controllers) and you will still get the error on find_package(ACE). This is because ACE is searched anyway, see iCubFindDependencies.cmake:52, even if you don't really need it.

[PeterBowman]

Consistency aside, I believe YARP users are now encouraged to load YCM prior to calling find_package(ACE) (or any other supported module). The YARP_MODULE_PATH variable is deprecated since YARP 3.0.0 (ref). If your devices used to rely on it to enhance the CMake module lookup path, you probably should add a find_package(YCM) line in your code.

[pattacini]

That's true, but not that straightforward for icub-main yet @PeterBowman
See https://github.com/robotology/icub-main/issues/534.

[Nicogene]

Fixed by 093d719a4e6cc1d9b4646be86f8b7d59067a42b7