When close_async() is called on a client with a sync transport, it logs only at DEBUG level and returns without closing the client. The transport remains active and resources are not released. This is problematic especially for __aexit__ (line 1144-1145) which calls close_async() - using async with client: with a sync transport will silently leave the client unclosed, potentially causing resource leaks.

In _patched_close(), calling loop.run_until_complete(_flush()) may raise a RuntimeError if the loop is already in the process of stopping or if this is called from within an async context. The current exception handling catches all exceptions and logs them, but this could mask underlying issues or result in events not being flushed. Additionally, if the loop is being closed from within a coroutine, run_until_complete will fail.

The test_transport_works_async test at line 932 has 5 parametrized dimensions: debug (2), client_flush_method (2), use_pickle (2), compression_level (3), and compression_algo (4). This creates 2×2×2×3×4 = 96 test combinations. Combined with inherent async test overhead, this may significantly slow down CI runs and makes debugging failures difficult.

The test_async_transport_background_thread_capture test at line 1004 sets the global scope's client via sentry_sdk.get_global_scope().set_client(client) but doesn't register a cleanup finalizer. If the test fails before await client.close_async(), the global scope remains modified for subsequent tests, potentially causing flaky test behavior.

Also found at:

• tests/test_transport.py:1046-1047