rclc_executor_spin_some returns RCL_RET_ERROR when using a custom transport

[NikoSalamini]

I am implementing a custom transport on FreeRTOS using the MicroBlaze processor. The transport is straightforward—it continuously polls memory, waiting for new data in the custom read function. I have already verified that the custom read function returns the correct number of bytes.

However, I am encountering the generic error "RCL_RET_ERROR". How can I effectively debug this issue? What does this generic error typically indicate?

[4ntn]

Hello, @NikoSalamini,

As you say, "RCL_RET_ERROR" is quite generic. It appears in different places in the rcl (https://github.com/micro-ROS/rcl) and the rclc (https://github.com/ros2/rclc).

Assuming you cannot use a step by step debugger on your setup, the best approach is usually to fork the package that is causing the problem and insert your custom debug prints. Then, modifying the build_micro_ros_library.sh script

micro_ros_vitis_component/build_micro_ros_library.sh

Lines 158 to 159 in 6ff8aed

	git clone -b ${MICRO_ROS_DISTRO} https://github.com/micro-ROS/rcl src/rcl;
	git clone -b ${MICRO_ROS_DISTRO} https://github.com/ros2/rclc src/rclc;

to clone the new branch from your fork.