Node action failing with some special parameters

[ivanpauno]

Bug report

• Operating System:
  • Ubuntu 18.04
• Installation type:
  • From source
• Version or commit hash:
  • launch_ros(#448846d9361f39bdde94d1a41679abac3a1e124a)
• DDS implementation:
  • fast-rtps
• Client library (if applicable):
  • rclcpp

Steps to reproduce issue

This is a modified version of launch_ros/examples/pub_sub_launch.py here.

# Copyright 2018 Open Source Robotics Foundation, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Launch a talker and a listener."""

import os
import sys
sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))  # noqa
sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', '..', 'launch'))  # noqa

from launch import LaunchDescription
from launch import LaunchIntrospector
from launch import LaunchService

from launch_ros import get_default_launch_description
import launch_ros.actions


def main(argv=sys.argv[1:]):
    """Main."""
    ld = LaunchDescription([
        launch_ros.actions.Node(
            package='demo_nodes_cpp', node_executable='talker', output='screen',
            node_name='my_node',
            parameters=[{'a': 1, 'b': 'a', 'c': ['list', 'of', 'stuff']}],
            remappings=[('chatter', 'my_chatter')]),
        launch_ros.actions.Node(
            package='demo_nodes_cpp', node_executable='listener', output='screen',
            remappings=[('chatter', 'my_chatter')]),
    ])

    print('Starting introspection of launch description...')
    print('')

    print(LaunchIntrospector().format_launch_description(ld))

    print('')
    print('Starting launch of launch description...')
    print('')

    # ls = LaunchService(debug=True)
    ls = LaunchService()
    ls.include_launch_description(get_default_launch_description())
    ls.include_launch_description(ld)
    return ls.run()


if __name__ == '__main__':
    main()

I only added:

            node_name='my_node',
            parameters=[{'a': 1, 'b': 'a', 'c': ['list', 'of', 'stuff']}],

Expected behavior

It should work as the original example.

Actual behavior

It fails when loading parameters.

Starting introspection of launch description...

<launch.launch_description.LaunchDescription object at 0x7fe2636a25c0>
├── ExecuteProcess(cmd=[ExecInPkg(pkg='demo_nodes_cpp', exec='talker'), LocalVar('node name'), LocalVar('parameter 1'), LocalVar('remapping 1')], cwd=None, env=None, shell=False)
└── ExecuteProcess(cmd=[ExecInPkg(pkg='demo_nodes_cpp', exec='listener'), LocalVar('remapping 1')], cwd=None, env=None, shell=False)

Starting launch of launch description...

[INFO] [launch]: All log files can be found below /home/ivanpauno/.ros/log/2019-04-11-15-07-37-242126-71c1584df2a2-4887
[INFO] [launch]: Default logging verbosity is set to INFO
[INFO] [talker-1]: process started with pid [4896]
[INFO] [listener-2]: process started with pid [4897]
[talker-1] terminate called after throwing an instance of 'std::runtime_error'
[talker-1]   what():  Failed to parse parameters from file '/tmp/launch_params_au9d6q_k': Sequence should be of same type. Value type 'bool' do not belong at line_num 8, at /home/ivanpauno/ros2_ws/src/ros2/rcl/rcl_yaml_param_parser/src/parser.c:891
[ERROR] [talker-1]: process has died [pid 4896, exit code -6, cmd '/home/ivanpauno/ros2_ws/install/demo_nodes_cpp/lib/demo_nodes_cpp/talker __node:=my_node __params:=/tmp/launch_params_au9d6q_k chatter:=my_chatter'].

Content of /tmp/launch_params_au9d6q_k

ivanpauno@71c1584df2a2:~/ros2_ws/src/ros2/launch_ros/launch_ros/examples$ cat /tmp/launch_params_au9d6q_k
/:
  my_node:
    ros__parameters:
      a: 1
      b: a
      c: !!python/tuple
      - list
      - of
      - stuff

Additional information

If I change the parameter arg to:

            parameters=[{'a': 1, 'b': 'a', 'c': ['a', 'b', 'c']}],

It works. Generated parameters file:

/:
  my_node:
    ros__parameters:
      a: 1
      b: a
      c: !!python/tuple
      - a
      - b
      - c

Numbers inside the 'c' list also work well, like ['10', '1', '2'].

As far as I've seen, the problem appears when one of the parameters is a list of strings, and one of the list items is more that one character long.

[ivanpauno]

Ok, I saw that the 'of' world is automatically recognized as a bool, and I used it on all my previous tests (super fun).
I think that it shouldn't be recognized like that (yaml boolean).
Also, if any of the yaml boolean keywords is between quotes ('On', 'True', etc), they shouldn't been converted to a bool. Now, the generated yaml file doesn't have quotes, and the rcl parser is still converting it to a bool.

I will open an issue later in rcl. I'm closing this one.