MoveIt2 Setup Assistant generated demo.launch.py error

[nilp-dromeda]

Description

After correctly following the MoveIt2 setup assistant tutorial, I decided to checkout if the output of the setup assistant was properly working. When running demo.launch.py it always ends in an error.

Your environment

• ROS Distro: [Humble
• OS Version: Ubuntu 20.04
• Using NixOS to build
• Source from this NixOS repo

Steps to reproduce

1. Use Moveit Setup Assistant to generate moveit_config package.
2. Run demo.launch.py

Expected behaviour

Rviz should pop up and nothing should crash.

Actual behaviour

Do not even get to the point of launching Rviz. Program is exited with the below error:

[ERROR] [launch]: Caught exception in launch (see debug for traceback): Expected 'value' to be one of [<class 'float'>, <class 'int'>, <class 'str'>, <class 'bool'>, <class 'bytes'>], but got '()' of type '<class 'tuple'>'