This PR fixes a bug found in foxy and newer distros that crashes the ROS 2 launch system when an argument with default_value='' is not overwritten. For some reason the empty string is internally converted to None, which raises the following error
File "/opt/ros/foxy/lib/python3.8/site-packages/launch_ros/utilities/evaluate_parameters.py", line 95, in evaluate_parameter_dict
raise TypeError(
TypeError: Allowed value types are bytes, bool, int, float, str, Sequence[bool], Sequence[int],
Sequence[float], Sequence[str]. Got <class 'NoneType'>. If the parameter is meant to be a string,
try wrapping it in launch_ros.parameter_descriptions.ParameterValue(value, value_type=str)
The easiest solution is to replace the empty string with a non-empty string. When an invalid spawn-point is passed, the node issues the following warning and then informs that a random spawn point was chosen
[WARN] [carla_spawn_objects]: Invalid spawnpoint 'None'
[INFO] [carla_spawn_objects]: Spawn point selected at random
If a spawn point is specified in the object description, the system issues the warnings
[WARN] [carla_spawn_objects]: Invalid spawnpoint 'None'
[WARN] [carla_spawn_objects]: ego_vehicle: Could not use spawn point from parameters, the spawn point from config file will be used.
After this messages, the launch system proceeds normally
This PR solves the problem described in #603, even without explicit goal of Carla 0.9.13 support. I believe that it is highly likely that people trying to run the newest Carla version are also running the newest version of ROS 2, thus facing the error described here. Personally, I was able to run ros bridge with Carla 0.9.13 smoothly after this fix.
This PR fixes a bug found in foxy and newer distros that crashes the ROS 2 launch system when an argument with
default_value=''is not overwritten. For some reason the empty string is internally converted toNone, which raises the following errorSimilar problems can be found https://github.com/introlab/rtabmap_ros/issues/725, https://github.com/LORD-MicroStrain/ntrip_client/pull/16 and https://github.com/microsoft/Azure_Kinect_ROS_Driver/issues/246
The easiest solution is to replace the empty string with a non-empty string. When an invalid spawn-point is passed, the node issues the following warning and then informs that a random spawn point was chosen
If a spawn point is specified in the object description, the system issues the warnings
After this messages, the launch system proceeds normally
This PR solves the problem described in #603, even without explicit goal of Carla 0.9.13 support. I believe that it is highly likely that people trying to run the newest Carla version are also running the newest version of ROS 2, thus facing the error described here. Personally, I was able to run ros bridge with Carla 0.9.13 smoothly after this fix.
This change is