# Bug report ### Bug description: ```text Python/specialize.c: In function ‘_Py_Specialize_ForIter’: Python/specialize.c:2392:60: error: incompatible type for argument 1 of ‘_PySpecialization_ClassifyIterator’ 2392 | _PySpecialization_ClassifyIterator(iter)); | ^~~~ | | | _PyStackRef Python/specialize.c:409:70: note: in definition of macro ‘SPECIALIZATION_FAIL’ 409 | _Py_stats->opcode_stats[opcode].specialization.failure_kinds[kind]++; \ | ^~~~ Python/specialize.c:2290:47: note: expected ‘PyObject *’ {aka ‘struct _object *’} but argument is of type ‘_PyStackRef’ 2290 | _PySpecialization_ClassifyIterator(PyObject *iter) | ~~~~~~~~~~^~~~ ``` Introduced after #118450 ### CPython versions tested on: CPython main branch ### Operating systems tested on: Linux <!-- gh-linked-prs --> ### Linked PRs * gh-121083 <!-- /gh-linked-prs -->