Attach, detach and reattach

[mehditlili]

I am currently having problems with attaching multiple times. When I spawn a model, attach its link to another model's link it works fine. Detaching also works fine. But when I try to reattach those two links again it doesn't work and I don't see any error message. I am using the melodic-devel branch so I was wondering if this also happens in the master branch.

[mehditlili]

Tested again with the simple demo provided with the package. Seems to work fine.
EDIT:
It fails when the model is spawned, attached, detached, then deleted, then respawned and attached again. I then start observing weird behaviour

[awesomebytes]

@mehditlili Sorry no one replied to you at the time. I may give it a try in a month... but I guess being a year later you are in no hurry. Did you find any workaround?

[mehditlili]

@awesomebytes I just avoided deleting objects. Or when I had to delete them, I made sure to respawn them under a different name.

[awesomebytes]

@mehditlili Thanks for the explanation! I'll make sure to test your bug too and see if I find how to fix it... Or in the worst case I could at least provide a warning that the behavior you describe is known to happen.

[dudasdavid]

@mehditlili I got a segmentation fault when detaching using your last commit, does it work for you?

With melodic-devel branch when I try to re-attach something I got a message: "Joint already existed, reusing it." and it says "Attach was succesful" but it doesn't re-attach in Gazebo. Please see my pull request #16 about a potential fix for the issue.

[Lincoln97]

Hi, I know it is been a while, but I am getting the exact same problem. I tried your fix but this segmentation fault keeps happening. Did you find any solution for this?

[dudasdavid]

@Lincoln97 , I only had problems during re-attach, and since that, I'm using my fork without any issues (and many many re-attach):
https://github.com/MOGI-ROS/gazebo_ros_link_attacher

What is the exact error you get?

Here is an example of my re-attach use case:
https://www.youtube.com/watch?v=eXZIVMFBH_Q&t