yarprobotinterface segmentation fault when closing a PolyDriver using remotecontrolboardremapper

[SuperDiodo]

Describe the bug

When the module exits (e.g., after pressing Ctrl+C) or when PolyDriver::close() is called, the remote yarpmotorinterface process crashes with a segmentation fault.

To Reproduce

1. Instantiate and open a PolyDriver configured to use the remotecontrolboardremapper device.
2. Configure the remoteControlBoards property to connect to one or more robot parts (e.g., head, torso, and right arm).
3. Acquire the required control interfaces and communicate with the robot.
4. Close the PolyDriver by calling PolyDriver::close(), or terminate the module with Ctrl+C.
5. Observe that the remote yarpmotorinterface process crashes with a segmentation fault.

Expected behavior

Closing the module with Ctrl+C or calling PolyDriver::close() should cleanly disconnect from the robot without affecting yarpmotorinterface. Instead, yarpmotorinterface crashes and prints the following log:

[ERROR] yarprobotinterface intercepted a segmentation fault caused by a faulty plugin:
[ERROR] /lib/x86_64-linux-gnu/libc.so.6(+0x84ae9) [0x7f31b4605ae9]
Trace requested at /usr/local/src/robot/robotology-superbuild/src/YARP/src/yarprobotinterface/Module.cpp:77 by code called from:
/usr/local/src/robot/robotology-superbuild/build/install/lib/libYARP_os.so.3(_Z16yarp_print_traceP8_IO_FILEPKcj+0x27) [0x7f31b4b0fb87]
yarprobotinterface(+0x950d) [0x55599e42750d]
/lib/x86_64-linux-gnu/libc.so.6(+0x37840) [0x7f31b45b8840]
/lib/x86_64-linux-gnu/libc.so.6(+0x84ae9) [0x7f31b4605ae9]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x7fc9) [0x7f31b2ac4fc9]
/lib/x86_64-linux-gnu/libc.so.6(clone+0x3f) [0x7f31b467a4cf]
Segmentation fault

Configuration (please complete the following information):

• OS: Ubuntu 24.04 LTS
• YARP version (client): 3.12 (module running on an external PC)
• YARP version (server): 3.09 (yarpmotorinterface running on the iCub head PC)
• Compiler: GCC 13.3.0

Additional context

The module controls joints belonging to different iCub parts (e.g., head, torso, and right arm) as a single logical unit through remotecontrolboardremapper.

The implementation is based on the following example:
https://github.com/traversaro/yarp-wholebody-motorcontrol-example/blob/master/yarpWholeBodyMotorControlExample.cpp

The module loads a joint trajectory from a CSV file and executes it.

The same implementation works correctly in Gazebo, where I can repeatedly start and stop the module without any issues.

The problem only occurs on the real iCub. After the module exits, the yarpmotorinterface process crashes, forcing me to perform an emergency stop on the robot and manually restart yarpmotorinterface before I can run the module again.

[SuperDiodo]

UPDATE

I performed some additional tests on a newer iCub. Although it is also running YARP 3.9 on the head PC, the hardware is newer and still supported, unlike the robot I originally tested on.

Interestingly, on this robot the segmentation fault when closing the PolyDriver no longer occurs. However, I still encounter a segmentation fault during execution.

I narrowed the issue down further.

My YARP module starts a thread that performs the following sequence:

1. Set the joints to POSITION mode.
2. Move the joints to an initial configuration using positionMove().
3. Wait until the motion completes.
4. Switch the joints to POSITION_DIRECT mode.
5. Stream the trajectory using setPositions().

During step 3, I was using yarp::dev::IPositionControl::getTargetPositions() to retrieve the target positions previously passed to positionMove(), in order to check whether the motion had completed. Calling getTargetPositions() consistently resulted in a segmentation fault.

I then modified the implementation to avoid calling getTargetPositions() and instead reused the same target configuration that had originally been passed to positionMove().

With this change, the segmentation fault no longer occurs.