Can't write launch tests with composable nodes about launch_ros

[hidmic]

The first error is expected, launch_test is ROS agnostic and will not automatically prepend the default launch description that's required for many launch_ros actions to work. One may argue that actions should be somewhat more verbose about their preconditions not being met instead of crashing.

The second error, which doesn't actually result in a test failure, is a combination of things. The test does run but it finishes so quickly that even though the container action is executed it doesn't have enough time to wrap up initialization and a signal gets sent "...before subprocess transport available". The second exception is somewhat peculiar, and I'd be inclined to think it's the result of not handling the first exception correctly.