new test failures on linux nightly

[wjwwood]

https://ci.ros2.org/view/nightly/job/nightly_linux_release/1323/testReport/

Specifically:

ament_package.test.test_flake8.test_flake8 | 2.8 sec | 1
-- | -- | --
test_launch_ros.test.test_launch_ros.frontend.test_node_frontend.test_node_frontend[\n<launch>\n     <let name="a_string" value="\\'[2, 5, 8]\\'"/>\n    <let  name="a_list" value="[2, 5, 8]"/>\n    <node pkg="demo_nodes_py"  exec="talker_qos" output="screen" name="my_node" namespace="my_ns"  args="--number_of_cycles 1">\n        <param name="param1"  value="ads"/>\n        <param name="param_group1">\n             <param name="param_group2">\n                <param  name="param2" value="2"/>\n            </param>\n             <param name="param3" value="2, 5, 8" value-sep=", "/>\n             <param name="param4" value="$(var a_list)"/>\n             <param name="param5" value="$(var a_string)"/>\n             <param name="param6" value="2., 5., 8." value-sep=", "/>\n             <param name="param7" value="'2', '5', '8'" value-sep=", "/>\n             <param name="param8" value="''2'', ''5'', ''8''"  value-sep=", "/>\n            <param name="param9" value="\\'2\\',  \\'5\\', \\'8\\'" value-sep=", "/>\n            <param  name="param10" value="''asd'', ''bsd'', ''csd''" value-sep=", "/>\n             <param name="param11" value="'\\asd', '\\bsd', '\\csd'"  value-sep=", "/>\n            <param name="param12"  value=""/>\n        </param>\n        <param  from="/home/jenkins-agent/workspace/nightly_linux_release/ws/src/ros2/launch_ros/test_launch_ros/test/test_launch_ros/frontend/params.yaml"/>\n         <env name="var" value="1"/>\n     </node>\n</launch>\n] | 55 ms | 1
test_launch_ros.test.test_launch_ros.frontend.test_node_frontend.test_node_frontend[\nlaunch:\n     - let:\n        name: 'a_string'\n        value: "'[2, 5, 8]'"\n    -  let:\n        name: 'a_list'\n        value: '[2, 5, 8]'\n    - node:\n         pkg: demo_nodes_py\n        exec: talker_qos\n        output:  screen\n        name: my_node\n        namespace: my_ns\n        args:  '--number_of_cycles 1'\n        param:\n            -   name: param1\n                 value: ads\n            -   name: param_group1\n                 param:\n                -   name: param_group2\n                     param:\n                    -   name: param2\n                         value: 2\n                -   name: param3\n                    value:  [2, 5, 8]\n                -   name: param4\n                    value:  $(var a_list)\n                -   name: param5\n                     value: $(var a_string)\n                -   name: param6\n                     value: [2., 5., 8.]\n                -   name: param7\n                     value: ['2', '5', '8']\n                -   name: param8\n                     value: ["'2'", "'5'", "'8'"]\n                -   name:  param9\n                    value: ["\\\\'2\\\\'", "\\\\'5\\\\'",  "\\\\'8\\\\'"]\n                -   name: param10\n                     value: ["'asd'", "'bsd'", "'csd'"]\n                -   name: param11\n                     value: ['\\asd', '\\bsd', '\\csd']\n                -    name: param12\n                    value: ''\n            -   from:  /home/jenkins-agent/workspace/nightly_linux_release/ws/src/ros2/launch_ros/test_launch_ros/test/test_launch_ros/frontend/params.yaml\n         env:\n            -   name: var\n                value: '1'\n]

I've seen these in my CI jobs as well (https://ci.ros2.org/job/ci_linux/8302/testReport/).

[wjwwood]

The ament_package one is hopefully fixed by this: ament/ament_package#96

[wjwwood]

For the two test_launch_ros failures, I've asked here since this pr was the only one merged since yesterday: ros2/launch_ros#82 (comment)