When an exception is thrown through the tracing middleware SentryTracingMiddleware, the transaction is finished and the exception flows through.

This means the exception captured by the erro reporting SentryMiddleware is unaware that there was a transaction in that request and the two parts of the product are disconnected

SentryTracingMiddleware must have a catch block and set that exception reference to the weak reference map that connects exception instances to spans, so that upstream we can do the link between error and transaction.