[noetic] wrap rostest call to add python pointing to sys.executable in PATH

[sloretz]

Another possible solution to #1830. This adds a temporary directory with a symlink to python to the path variable.

This uses tempfile.TemporaryDirectory which is only available in python 3.2 and above, so it must not be merged onto the melodic-devel branch. With this PR (and #1870) I don't see any ros_comm tests using Python 2, though many tests raise ModuleNotFoundError when trying to import other packages.

[dirk-thomas]

though many tests raise ModuleNotFoundError when trying to import other packages.

Can you please reference some of the failing tests here to be able to determine what might cause this.

[sloretz]

Can you please reference some of the failing tests here to be able to determine what might cause this.

======================================================================
ERROR: test_validate_master_launch (unit.test_roslaunch_launch.TestRoslaunchLaunch)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/sloretz/ws/noetic/src/ros_comm/tools/roslaunch/test/unit/test_roslaunch_launch.py", line 47, in test_validate_master_launch
    import roslaunch.launch
  File "/home/sloretz/ws/noetic/src/ros_comm/tools/roslaunch/src/roslaunch/__init__.py", line 62, in <module>
    from .scriptapi import ROSLaunch
  File "/home/sloretz/ws/noetic/src/ros_comm/tools/roslaunch/src/roslaunch/scriptapi.py", line 42, in <module>
    import roslaunch.parent
  File "/home/sloretz/ws/noetic/src/ros_comm/tools/roslaunch/src/roslaunch/parent.py", line 54, in <module>
    import roslaunch.server
  File "/home/sloretz/ws/noetic/src/ros_comm/tools/roslaunch/src/roslaunch/server.py", line 79, in <module>
    from rosgraph_msgs.msg import Log
ModuleNotFoundError: No module named 'rosgraph_msgs'

[dirk-thomas]

That test (roslaunch/test/unit/test_roslaunch_launch.py) isn't run by rostest but nose, right? So this change wouldn't have any effect.

[sloretz]

That test (roslaunch/test/unit/test_roslaunch_launch.py) isn't run by rostest but nose, right? So this change wouldn't have any effect.

Yeah it seems unrelated to this PR. rosgraph_msgs doesn't appear to be part of the underlay when building with catkin_make_isolated. No clue why yet, but I'll move that to a separate issue.

[dirk-thomas]

rosgraph_msgs doesn't appear to be part of the underlay when building with catkin_make_isolated.

I am surprised since it is a declared dependency:

ros_comm/test/test_rosbag/package.xml

Line 35 in aedcece

<build_depend>rosgraph_msgs</build_depend>

[dirk-thomas]

lgtm

[sloretz]

@ros-pull-request-builder retest this please

edit: test failures, rerunning to check for flakiness, these are the old tests

• http://build.ros.org/job/Mpr__ros_comm__ubuntu_bionic_amd64/284/
• http://build.ros.org/job/Mpr_ds__ros_comm__debian_stretch_amd64/275/
• http://build.ros.org/job/Npr__ros_comm__ubuntu_focal_amd64/117/
• http://build.ros.org/job/Npr_db__ros_comm__debian_buster_amd64/116/

[sloretz]

@ros-pull-request-builder retest this please

[dirk-thomas]

Just waiting for the noetic-devel branch to be created.