RuntimeError: Spawn failed because of collision at spawn position

[asevenster]

When the following error occurs
RuntimeError: Spawn failed because of collision at spawn position
JOAN freezes and you have to restart the program and your experiment.

[OlgerSiebinga]

This seems to be a generic problem with all JOAN modules. If an exception occurs in the get_ready() function of a module, the except_hook is called but the process is not terminated correctly. But I'm not sure what exactly is happening.

[niekbeckers]

On top of Olger's answer - the origin of the problem is that CARLA tries to spawn a car on top of another already existing car. The existing car is there because a) CARLA hasn't disposed of it properly, b) JOAN hasn't disposed of the car properly (e.g. due to a crash of JOAN). One approach is to check what cars are already spawned in CARLA before spawning new cars to avoid this issue.

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On Thu, Jul 1, 2021 at 1:07 PM Olger Siebinga ***@***.***> wrote: This seems to be a generic problem with all JOAN modules. If an exception occurs in the get_ready() function of a module, the except_hook is called but the process is not terminated correctly. But I'm not sure what exactly is happening. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#2 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACZPCYY4YUGHHILLW3JNXVLTVRD6XANCNFSM46NPFJWQ> .

[OlgerSiebinga]

Turns out the module manager got stuck in an infinite loop because it was waiting for the get_ready() function to trigger the module_is_ready event. The excepthook exited the process before this event was set, causing the module manager to hang. This issue was fixed in commit a99a022 by setting the event from the excepthook before exiting.