[nav2_bringup] Error handling on bringup #1078
Description
It took me a few minutes to debug something like:
[ERROR] [launch]: Caught exception in launch (see debug for traceback): Caught exception when trying to load file of format [{}]:
Lovely little error. What ended up happening is I traced it back to
declare_world_cmd = launch.actions.DeclareLaunchArgument(
'world',
default_value=os.path.join(get_package_share_directory('turtlebot3_gazebo'),
'worlds/turtlebot3_worlds/waffle.model'),
description='Full path to world file to load')
And because I didnt have turtlebot3_gazebo in my path, it failed to find it. There should be some error thrown here that turtlebot3_gazebo is not found rather than just crashing