The change of making "tstate->exc_state" a struct was introduced in CPython...

The change of making "tstate->exc_state" a struct was introduced in CPython 3.7.0a3 and not 3.7.0a2, which some people still seem to be using right now.

Cython/Utility/Coroutine.c

@@ -1851,7 +1851,7 @@ static void __Pyx__ReturnWithStopIteration(PyObject* value) {
     }
     #if CYTHON_FAST_THREAD_STATE
     __Pyx_PyThreadState_assign
-    #if PY_VERSION_HEX >= 0x030700A2
+    #if PY_VERSION_HEX >= 0x030700A3
     if (!$local_tstate_cname->exc_state.exc_type)
     #else
     if (!$local_tstate_cname->exc_type)

Cython/Utility/Exceptions.c

@@ -359,7 +359,7 @@ static int __Pyx_GetException(PyObject **type, PyObject **value, PyObject **tb)
     *value = local_value;
     *tb = local_tb;
 #if CYTHON_FAST_THREAD_STATE
-    #if PY_VERSION_HEX >= 0x030700A2
+    #if PY_VERSION_HEX >= 0x030700A3
     tmp_type = tstate->exc_state.exc_type;
     tmp_value = tstate->exc_state.exc_value;
     tmp_tb = tstate->exc_state.exc_traceback;
@@ -403,7 +403,7 @@ static CYTHON_INLINE void __Pyx_ReraiseException(void) {
     PyObject *type = NULL, *value = NULL, *tb = NULL;
 #if CYTHON_FAST_THREAD_STATE
     PyThreadState *tstate = PyThreadState_GET();
-    #if PY_VERSION_HEX >= 0x030700A2
+    #if PY_VERSION_HEX >= 0x030700A3
     type = tstate->exc_state.exc_type;
     value = tstate->exc_state.exc_value;
     tb = tstate->exc_state.exc_traceback;
@@ -455,7 +455,7 @@ static CYTHON_INLINE void __Pyx__ExceptionReset(PyThreadState *tstate, PyObject
 
 #if CYTHON_FAST_THREAD_STATE
 static CYTHON_INLINE void __Pyx__ExceptionSave(PyThreadState *tstate, PyObject **type, PyObject **value, PyObject **tb) {
-    #if PY_VERSION_HEX >= 0x030700A2
+    #if PY_VERSION_HEX >= 0x030700A3
     *type = tstate->exc_state.exc_type;
     *value = tstate->exc_state.exc_value;
     *tb = tstate->exc_state.exc_traceback;
@@ -472,7 +472,7 @@ static CYTHON_INLINE void __Pyx__ExceptionSave(PyThreadState *tstate, PyObject *
 static CYTHON_INLINE void __Pyx__ExceptionReset(PyThreadState *tstate, PyObject *type, PyObject *value, PyObject *tb) {
     PyObject *tmp_type, *tmp_value, *tmp_tb;
 
-    #if PY_VERSION_HEX >= 0x030700A2
+    #if PY_VERSION_HEX >= 0x030700A3
     tmp_type = tstate->exc_state.exc_type;
     tmp_value = tstate->exc_state.exc_value;
     tmp_tb = tstate->exc_state.exc_traceback;
@@ -510,7 +510,7 @@ static CYTHON_INLINE void __Pyx_ExceptionSwap(PyObject **type, PyObject **value,
 static CYTHON_INLINE void __Pyx__ExceptionSwap(PyThreadState *tstate, PyObject **type, PyObject **value, PyObject **tb) {
     PyObject *tmp_type, *tmp_value, *tmp_tb;
 
-    #if PY_VERSION_HEX >= 0x030700A2
+    #if PY_VERSION_HEX >= 0x030700A3
     tmp_type = tstate->exc_state.exc_type;
     tmp_value = tstate->exc_state.exc_value;
     tmp_tb = tstate->exc_state.exc_traceback;