Index: Python/pythonrun.c
===================================================================
--- Python/pythonrun.c	(Revision 88649)
+++ Python/pythonrun.c	(Arbeitskopie)
@@ -2052,6 +2052,9 @@
     case E_IDENTIFIER:
         msg = "invalid character in identifier";
         break;
+    case E_TOONESTED:
+        PyErr_SetString(PyExc_MemoryError, "too many opening parens");
+        goto cleanup;
     default:
         fprintf(stderr, "error=%d\n", err->error);
         msg = "unknown parsing error";
Index: Include/errcode.h
===================================================================
--- Include/errcode.h	(Revision 88649)
+++ Include/errcode.h	(Arbeitskopie)
@@ -30,6 +30,7 @@
 #define E_EOLS		24	/* EOL in single-quoted string */
 #define E_LINECONT	25	/* Unexpected characters after a line continuation */
 #define E_IDENTIFIER    26      /* Invalid characters in identifier */
+#define E_TOONESTED     27      /* Too many opening parens */
 
 #ifdef __cplusplus
 }
Index: Parser/parser.c
===================================================================
--- Parser/parser.c	(Revision 88649)
+++ Parser/parser.c	(Arbeitskopie)
@@ -39,8 +39,7 @@
 {
     register stackentry *top;
     if (s->s_top == s->s_base) {
-        fprintf(stderr, "s_push: parser stack overflow\n");
-        return E_NOMEM;
+        return E_TOONESTED;
     }
     top = --s->s_top;
     top->s_dfa = d;
Index: Lib/test/test_parser.py
===================================================================
--- Lib/test/test_parser.py	(Revision 88649)
+++ Lib/test/test_parser.py	(Arbeitskopie)
@@ -542,9 +542,6 @@
 
     def test_trigger_memory_error(self):
         e = self._nested_expression(100)
-        print("Expecting 's_push: parser stack overflow' in next line",
-              file=sys.stderr)
-        sys.stderr.flush()
         self.assertRaises(MemoryError, parser.expr, e)
 
 class STObjectTestCase(unittest.TestCase):