tests pass in a cython 3.0.2 environment

freud/box.pyx

@@ -718,15 +718,7 @@ cdef class Box:
             pass
         return NotImplemented
 
-    def __mul__(arg1, arg2):
-        # Note Cython treats __mul__ and __rmul__ as one operation, so
-        # type checks are necessary.
-        if isinstance(arg1, freud.box.Box):
-            self = arg1
-            scale = arg2
-        else:
-            scale = arg1
-            self = arg2
+    def _mul_impl(self, scale):
         if scale > 0:
             return self.__class__(Lx=self.Lx*scale,
                                   Ly=self.Ly*scale,
@@ -736,6 +728,12 @@ cdef class Box:
         else:
             raise ValueError("Box can only be multiplied by positive values.")
 
+    def __mul__(self, scale):
+        return self._mul_impl(scale)
+
+    def __rmul__(self, scale):
+        return self._mul_impl(scale)
+
     def plot(self, title=None, ax=None, image=[0, 0, 0], *args, **kwargs):
         """Plot a :class:`~.box.Box` object.
 

freud/locality.pyx

@@ -201,7 +201,7 @@ cdef class NeighborQueryResult:
             yield (npoint.query_point_idx, npoint.point_idx, npoint.distance)
             npoint = dereference(iterator).next()
 
-        raise StopIteration
+        return
 
     def toNeighborList(self, sort_by_distance=False):
         """Convert query result to a freud :class:`~NeighborList`.