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This test case originated from c2b0b12, and the new behaviour it's actually attempting to verify is:

1. In debug mode, module creation automatically invokes the registered traverse function (for eager detection of problematic traversal function definitions)
2. When the traversal function isn't checking correctly for a valid module state, the module creation fails

Actually implementing a valid traversal function here isn't overly important, as the module using it never actually gets created.

So I think @taleinat's right that this bad traversal function can be simplified to avoid the #ifdef, but I think it can be simplified all the way to being just:

m_state = PyModule_GetState(self);
/* The following assertion mimics any traversal function that doesn't correctly handle
 * the case during module creation where the module state hasn't been created yet.
 */
assert(m_state != NULL);
Py_VISIT(m_state->integer);
return 0;

That way the case of interest will always fail on the assert() call, and never even attempt to dereference the pointer.