Launch command not found

On activating the ros-foxy environment, the launch command is not available by default. As a result,

ros2 launch ... ... results in the following error:

Failed to load entry point 'launch': Environment variable 'AMENT_PREFIX_PATH' is not set or empty
Traceback (most recent call last):
  File "/Users/me/miniconda3/envs/ros-foxy/bin/ros2", line 8, in <module>
    sys.exit(main())
  File "/Users/me/miniconda3/envs/ros-foxy/lib/python3.8/site-packages/ros2cli/cli.py", line 39, in main
    add_subparsers_on_demand(
  File "/Users/me/miniconda3/envs/ros-foxy/lib/python3.8/site-packages/ros2cli/command/__init__.py", line 236, in add_subparsers_on_demand
    extension = command_extensions[name]
KeyError: 'launch'

The full list of commands (on running ros2) are:

Commands:
  action     Various action related sub-commands
  bag        Various rosbag related sub-commands
  component  Various component related sub-commands
  daemon     Various daemon related sub-commands
  doctor     Check ROS setup and other potential issues
  interface  Show information about ROS interfaces
  lifecycle  Various lifecycle related sub-commands
  multicast  Various multicast related sub-commands
  node       Various node related sub-commands
  param      Various param related sub-commands
  pkg        Various package related sub-commands
  run        Run a package specific executable
  service    Various service related sub-commands
  topic      Various topic related sub-commands
  wtf        Use `wtf` as alias to `doctor`

Start by reproducing the issue after activating the ros-foxy environment and running ros2 launch, then compare the available ros2 commands with the traceback involving AMENT_PREFIX_PATH. Done means the launch command is available by default and no environment-variable or KeyError failure occurs.