The _finished attribute is declared in __slots__ but never initialized in __init__. When _end() is called, the check if self._finished: on line 485 will raise an AttributeError because the attribute doesn't exist yet. This affects every NoOpStreamedSpan when it finishes, breaking span cleanup.

When a child span is created from a NoOpStreamedSpan parent (line 1235), the new NoOpStreamedSpan is instantiated without the scope parameter. While this causes _start() to return early (since self._scope is None), the _finished attribute is never initialized in NoOpStreamedSpan.__init__(). When _end() is later called (e.g., via the context manager __exit__ or explicit end() call), it accesses self._finished before any assignment, causing an AttributeError: 'NoOpStreamedSpan' object has no attribute '_finished'.

Also found at:

• sentry_sdk/traces.py:485-486

The _update_sample_rate method modifies baggage.sentry_items["sample_rate"] without checking if the baggage is mutable. According to the Baggage class documentation, callers must check baggage.mutable is True before mutation. When a trace is continued from an incoming header containing sentry items, the baggage is immutable (mutable=False), so this modification violates the baggage contract and could lead to unexpected behavior in trace propagation.