Negative cargo race condition bug in transfer cargo #110

I have a bugged ship, it fails to fetch on both the ships listing and single ship endpoints. Here is the returned error:

{"error":{"code":3000,"message":"The server did not return a valid response. If you want to help you can file an issue here: https://github.com/SpaceTradersAPI/api-docs.","requestId":"019790c7-bd34-71e9-b907-36ed2e4c82c6"}}

It's ship RJ45-22 in the current reset (2025-06-15). It's a mining drone.

I have had this happen on both the prod and staging servers.

There's a chance it's a race condition in the cargo transfer code 'cause my client used to not be super careful to ensure that the cargo of the ship it's transferring to was not full, and I had several agents all transferring at the same time, which could result in two transfer cargo requests at the same time to the server for different ships to both fill the target ship (which was a hauler).

I have since changed my logic so the hauler pulls cargo from the drones rather than the drones pushing to it so if I am right it shouldn't happen again. But I will report if that's not the case.

edit: the /cargo endpoint fails, but the /nav endpoint succeeds. So a bit more evidence that the cargo transfer is the issue.