PX4-Autopilot: px4_sitl_rtps doesn't work with px4_ros_com micrortps_bridge

Describe the bug

In the master branch of this repo (from about a month ago), I could follow the steps described here to get data from the px4_sitl_rtps gazebo simulator to cross the micrortps bridge and show up in ROS2. I could also run the offboard_mode example with ROS2. Around July 8, the master branch of this repo was merged into main. When that occurred, data from the px4_sitl_rtps gazebo simulator would be sent over the micrortps bridge, but the micrortps_agent would die with this error:

terminate called after throwing an instance of 'eprosima::fastcdr::exception::BadParamException'
  what():  Unexpected byte value in Cdr::deserialize(bool), expected 0 or 1
Aborted (core dumped)

I believe the bug is associated with this issue/fix, which was made on the master branch, but doesn’t appear to be fully integrated into the main branch. The first file seems fine. The second file doesn’t. I tried editing the second file associated with this MR (which appears to be renamed slightly to msg/templates/uorb_microcdr/msg.cpp.em), but was unable to get it to work.

When I revert the repo to an earlier version (i.e., right before the master -> main merge by using git checkout 10a2b4c9f7d34234459b4d3604b99a33491a9d83), everything works properly (i.e., data is sent over the micrortps bridge, the micrortps_agent receives it, and you can ros2 topic echo any of the messages).

I have checked whether the px4_msgs or px4_ros_com repos have changed in the previous month. They have not. The source of the miscommunication across the micrortps bridge appears to be associated with recent changes to the PX4-Autopilot repo.

To Reproduce

Steps to reproduce the behavior:

1. In terminal 1, get the latest version of this repo and start the simulator:

   git clone https://github.com/PX4/PX4-Autopilot --recursive
   cd ~/PX4-Autopilot
   make
   make px4_sitl_rtps
   make px4_sitl_rtps gazebo
   

2. In terminal 2, follow the steps described here to install Fast-DDS, ROS2, and the px4_ros_com_ros2 workspace. When running the sanity check the installation section, you will run these commands:

   source ~/px4_ros_com_ros2/install/setup.bash
   micrortps_agent -t UDP
   

   which will produce this error:

   terminate called after throwing an instance of 'eprosima::fastcdr::exception::BadParamException'
     what():  Unexpected byte value in Cdr::deserialize(bool), expected 0 or 1
   Aborted (core dumped)
   

3. In terminal 1, revert the PX4-Autopilot to an earlier version and restart the simulator:

   cd ~/PX4-Autopilot
   git checkout 10a2b4c9f7d34234459b4d3604b99a33491a9d83
   make
   make px4_sitl_rtps
   make px4_sitl_rtps gazebo
   

4. In terminal 2, restart the micrortps_agent (micrortps_agent -t UDP). It should not die.
5. In terminal 3, you can now ros2 topic echo any of the fields and it will print out data:

   ros2 topic echo /fmu/sensor_combined/out
   ---
   timestamp: 1657838030351792
   gyro_rad:
   - -0.0005326324608176947
   - -0.0007989492150954902
   - -0.0007989475270733237
   gyro_integral_dt: 4000
   accelerometer_timestamp_relative: 0
   accelerometer_m_s2:
   - 0.06823474913835526
   - 0.07062912732362747
   - -9.889251708984375
   accelerometer_integral_dt: 4000
   accelerometer_clipping: 0
   gyro_clipping: 0
   accel_calibration_count: 0
   gyro_calibration_count: 1
   

Expected behavior

There should be no error when performing step 2 above.

Log Files and Screenshots

N/A

Drone:

px4_sitl_rtps (iris rtps)

Additional context

None