New GitHub issue #115709 from markshannon:<br>
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<pre>
# Bug report
### Bug description:
Consider
```Py
def testfunc(loops):
for _ in range(loops):
a = 1
a + a
a + a
change_a()
a + a
```
and suppose that `change_a` manages to change the value of the local `a` to `"a"`.
Specialization will have converted the subsequent `a + a` to integer addition, and type propagation will have stripped the guard, resulting in a crash.
This is incredibly unlikely, and very hard to come up with a test for but it is theoretically possible.
It may be become more likely (and easier to test for) if PEP 667 is accepted.
### CPython versions tested on:
3.13
### Operating systems tested on:
Other
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<a href="https://github.com/python/cpython/issues/115709">View on GitHub</a>
<p>Labels: type-bug, 3.13</p>
<p>Assignee: </p>