- Finally fixed the bug in compile() and exec where a string ending

with an indented code block but no newline would raise SyntaxError.
  This would have been a four-line change in parsetok.c...  Except
  codeop.py depends on this behavior, so a compilation flag had to be
  invented that causes the tokenizer to revert to the old behavior;
  this required extra changes to 2 .h files, 2 .c files, and 2 .py
  files.  (Fixes SF bug #501622.)

Lib/code.py

@@ -303,4 +303,5 @@ def interact(banner=None, readfunc=None, local=None):
 
 
 if __name__ == '__main__':
-    interact()
+    import pdb
+    pdb.run("interact()\n")