How to get MicroROS thread support for Zephyr

[Johannes-42]

Issue template

• Hardware description: Olimex STM32-E407
• RTOS: Zephyr
• Installation type: -
• Version or commit hash: -

Steps to reproduce the issue

Set up MicroROS like in the Tutorial: https://micro.ros.org/docs/tutorials/core/first_application_rtos/zephyr/
Then add:
"microxrcedds_client": {
"cmake-args": [
"-DUCLIENT_PROFILE_MULTITHREAD=ON"
]
}
to the app-colcon.meta file.

Expected behavior

Enable multithreading.

Actual behavior

zephyr/microros_ws/firmware/mcu_ws/eProsima/Micro-XRCE-DDS-Client/include/uxr/client/profile/multithread/multithread.h:49:20: error: field 'impl' has incomplete type
49 | struct k_mutex impl;

Additional information

Same as #668 but for Zephyr and not freeRTOS
Which directories do I need to include? (I guess in the arm_toolchain.cmake.in)

[czarekk215]

@pablogs9 Do you know what can cause error?