show "except *" declaration in error messages to help distinguishing between incompatible types

Cython/Compiler/PyrexTypes.py

@@ -2710,8 +2710,9 @@ class CFuncType(CType):
                 trailer = " except %s" % self.exception_value
             elif self.exception_check == '+':
                 trailer = " except +"
-            else:
-                " except *" # ignored
+            elif self.exception_check and for_display:
+                # not spelled out by default, unless for human eyes
+                trailer = " except *"
             if self.nogil:
                 trailer += " nogil"
         if not with_calling_convention: