core: stdcm: conflicts in post-processing

[eckter]

What happened?

{
    "status": 500,
    "type": "core:unknown_error",
    "context": {
        "stack_trace": [
            "PostProcessingSimulation.kt:472",
            "PostProcessingSimulation.kt:104",
            "PostProcessingSimulation.kt:457",
            "PostProcessingSimulation.kt:104",
            "PostProcessingSimulation.kt:51",
            "STDCMPostProcessing.kt:81",
            "STDCMPathfinding.kt:134",
            "STDCMPathfinding.kt:77",
            "STDCMEndpointV2.kt:104",
            "WorkerCommand.kt:249",
            "WorkerCommand.kt:303",
            "ContextPropagatingRunnable.java:37",
            "ThreadPoolExecutor.java:1144",
            "ThreadPoolExecutor.java:642",
            "Thread.java:1583"
        ],
        "message": "Failed to compute a simulation that wouldn't cause conflicts: mismatch between exploration and postprocessing (please open a bug report)",
        "exception_type": "class java.lang.RuntimeException",
        "url": "/v2/stdcm"
    },
    "message": "An unknown exception was thrown"
}

What did you expect to happen?

No response

How can we reproduce it (as minimally and precisely as possible)?

Running the fuzzer is a way to reproduce it, it just happens "randomly"

On which environments the bug occurs?

Local

On which browser the bug occurs?

Firefox

OSRD version (top right corner Account button > Informations)

0ee63cf