class A:    def __buffer__(self, flags):            return memoryview(bytes(8))    def __release_buffer__(self, view):            pass # do not need to do anything here, just needs to existb = bytearray(8)m = memoryview(b) # now b.extend will raise an exception due to exportsb.extend(A())

In a debug build this crashes withAssertion failed: (!PyErr_Occurred()), function _PyType_Lookup, file typeobject.c, line 4707.

Reported by@chilaxan. I'll work on a fix later today.

Most likely, the fix will be to callPyErr_Fetch/PyErr_Restore around calls to Python__release_buffer__ methods.

Linked PRs

• gh-104371: Fix calls to __release_buffer__ while an exception is active #104378
• GH-104371: check return value of callingmv.release #104417