tools using daemon crash if default rmw implementation is not installed #120
Description
Working from binaries, if the default rmw_implementation is removed and the ros2 tools invoked without specifying the RMW_IMPLEMENTATION the tools crash with a Traceback without useful error message.
Details
root@10328256cca9:~# ros2 topic list
Traceback (most recent call last):
File "/opt/ros/bouncy/bin/ros2", line 11, in <module>
load_entry_point('ros2cli==0.5.2', 'console_scripts', 'ros2')()
File "/opt/ros/bouncy/lib/python3.6/site-packages/ros2cli/cli.py", line 69, in main
rc = extension.main(parser=parser, args=args)
File "/opt/ros/bouncy/lib/python3.6/site-packages/ros2topic/command/topic.py", line 43, in main
return extension.main(args=args)
File "/opt/ros/bouncy/lib/python3.6/site-packages/ros2topic/verb/list.py", line 34, in main
with NodeStrategy(args) as node:
File "/opt/ros/bouncy/lib/python3.6/site-packages/ros2cli/node/strategy.py", line 29, in __init__
spawn_daemon(args)
File "/opt/ros/bouncy/lib/python3.6/site-packages/ros2cli/node/daemon.py", line 72, in spawn_daemon
stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, **kwargs)
File "/usr/lib/python3.6/subprocess.py", line 709, in __init__
restore_signals, start_new_session)
File "/usr/lib/python3.6/subprocess.py", line 1275, in _execute_child
restore_signals, start_new_session, preexec_fn)
TypeError: expected str, bytes or os.PathLike object, not NoneType
root@10328256cca9:~# ros2 node list
Traceback (most recent call last):
File "/opt/ros/bouncy/bin/ros2", line 11, in <module>
load_entry_point('ros2cli==0.5.2', 'console_scripts', 'ros2')()
File "/opt/ros/bouncy/lib/python3.6/site-packages/ros2cli/cli.py", line 69, in main
rc = extension.main(parser=parser, args=args)
File "/opt/ros/bouncy/lib/python3.6/site-packages/ros2node/command/node.py", line 39, in main
return extension.main(args=args)
File "/opt/ros/bouncy/lib/python3.6/site-packages/ros2node/verb/list.py", line 34, in main
with NodeStrategy(args) as node:
File "/opt/ros/bouncy/lib/python3.6/site-packages/ros2cli/node/strategy.py", line 29, in __init__
spawn_daemon(args)
File "/opt/ros/bouncy/lib/python3.6/site-packages/ros2cli/node/daemon.py", line 72, in spawn_daemon
stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, **kwargs)
File "/usr/lib/python3.6/subprocess.py", line 709, in __init__
restore_signals, start_new_session)
File "/usr/lib/python3.6/subprocess.py", line 1275, in _execute_child
restore_signals, start_new_session, preexec_fn)
TypeError: expected str, bytes or os.PathLike object, not NoneType
How to reproduce:
$ docker run -it --rm osrf/ros2:bouncy-basic
# apt update && apt install -y ros-bouncy-rmw-opensplice-cpp
# apt remove ros-bouncy-rmw-fastrtps-cpp -y && apt autoremove -y
# source /opt/ros/bouncy/setup.bash
# ros2 node list