[smarc_bt] Crashes on startup

[nilsbore]

When I try to run the new code from a devel workspace, I get the following crash on startup:

            smarc_bt: Traceback (most recent call last):
            smarc_bt:   File "/home/nbore/Workspace/ros/dr_sim_ws/devel/lib/smar
                   ~  c_bt/smarc_bt.py", line 15, in <module>
            smarc_bt:     exec(compile(fh.read(), python_script, 'exec'), contex
                   ~  t)
            smarc_bt:   File "/home/nbore/Workspace/ros/dr_sim_ws/src/smarc_miss
                   ~  ions/smarc_bt/src/smarc_bt.py", line 24, in <module>
            smarc_bt:     from auv_config import AUVConfig
            smarc_bt: ModuleNotFoundError: No module named 'auv_config'

[nilsbore]

Alright, I realized why this was and it's not an error on your part. I think it's because auv_config still has the original python shebang in there, which is replaced when using the catkin_install_python command that's used to create the install space.

[nilsbore]

It works with an install space as I though but I do not understand why it does not work from a devel space (I replaced with the correct shebang and it still doesn't work). It looks like noetic has some mechanic for dealing with this to make it work even for a devel space. I suspect it's this mechanic that doesn't work because your python project setup is not exactly standard.

[cisprague]

What do you mean by standard?

[KKalem]

I had tried making the __init__.py, the folder structure etc. of "standard" python projects, then it worked in devel space but this time not in install space, so I opted for keeping it running in install.

[nilsbore]

Ok! So what did you have to do to make it work with an install space?

[nilsbore]

@cisprague E.g. this is a pretty good tutorial for how ROS python packages are typically structured: http://www.artificialhumancompanions.com/structure-python-based-ros-package/ . Note that this was before the new catkin_install_python cmake thing for python3 compatibility.

[nilsbore]

I'm gonna guess that it might be the absence of a setup.py file that confuses catkin. It's a bit tricky to say what's happening since everything is imported basically as local imports.

[cisprague]

Can we get away with it for now while we work on other things? Then, later, we can emulate what is described in the link you shared.

[nilsbore]

Yes, we can get away with this for now. However, we need to think about how it should work on the vehicle. ATM, we are using a devel workspace there. But I guess that should still work with melodic. Can you confirm that devel workspace works with melodic?

[cisprague]

I cannot, I am using Noetic.

[KKalem]

Confirmed working in Melodic devel space on LoLo yesterday.