Fresh install of Moveit 2 demo failing on "libexec directory missing"

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New to Ros2. I installed the Moveit! package following the instructions here: https://moveit.ros.org/install-moveit..., running ubuntu 20.04 on x86_64 pc, kernel 5.8.0-44-generic. (ROS_VERSION=2 ROS_PYTHON_VERSION=3 ROS_LOCALHOST_ONLY=0 ROS_DISTRO=foxy )

The compilation/installation works fine, but when trying the demo as per instuction here: https://github.com/ros-planning/movei...

with command:

ros2 launch run_moveit_cpp run_moveit_cpp.launch.py

it fails.

Rviz starts normally, I see the panda robot for 2 seconds and then rviz crashes. The main errors seem to be of the type: "but libexec directory '....../ws_moveit2/install/run_moveit_cpp/lib/run_moveit_cpp' does not exist"

The full output of the command is below.

I also tried to run the moveit package in the provided LXD container(https://moveit.ros.org/inst.... I got exactly the same problems there.

Any ideas? When googling I found some comments about missing setup.cfg files which could lead to this kind of issues, but it seems strange that this would be the cause and would mean dozens of setup.cfg files would be missing as there is currently not a single setup.cfg in the whole ws_moveit2/ tree.

Is there something missing from the instructions ( I tried several times with same result) or is there some workaround I could use?

[INFO] [launch]: All log files can be found below /home/paul/.ros/log/2021-03-12-13-43-09-841286-pc-30027
[INFO] [launch]: Default logging verbosity is set to INFO
Task exception was never retrieved
future: <Task finished name='Task-2' coro=<LaunchService._process_one_event() done, defined at /opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py:271> exception=SubstitutionFailure("package 'run_moveit_cpp' found at '/home/paul/ws_moveit2/install/run_moveit_cpp', but libexec directory '/home/paul/ws_moveit2/install/run_moveit_cpp/lib/run_moveit_cpp' does not exist")>
Traceback (most recent call last):
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 273, in _process_one_event
    await self.__process_event(next_event)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 293, in __process_event
    visit_all_entities_and_collect_futures(entity, self.__context))
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
    futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
    futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
    futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
  [Previous line repeated 1 more time]
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 38, in visit_all_entities_and_collect_futures
    sub_entities = entity.visit(context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/action.py", line 108, in visit
    return self.execute(context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch_ros/actions/node.py", line 426, in execute
    ret = super().execute(context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/actions/execute_process.py", line 775, in execute
    self.__expand_substitutions(context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/actions/execute_process.py", line 635, in __expand_substitutions
    cmd = [perform_substitutions(context, x) for x in self.__cmd]
  File "/opt ...