Running the PCBuild\rt.bat script fails when it compares the expected output
with the actual output.  Some inspection shows that the comparison fails
because
there are '\n' linefeeds in the expected and '\n\r' linefeeds in the
actual output:

  c:\svn\py3k\PCbuild>python_d  -E -tt ../lib/test/regrtest.py
  test_grammar
  test test_grammar produced unexpected output:
  **********************************************************************
  *** mismatch between line 1 of expected output and line 1 of actual
output:
  - test_grammar
  + test_grammar
  ?             +
  (['test_grammar\n'], ['test_grammar\r\n'])
  ... and so on ...

(The last line is printed by some code I added to Lib\regrtest.py.)

It seems that this behaviour was introduced by r57186:

  New I/O code from Tony Lownds implement newline feature correctly,
  and implements .newlines attribute in a 2.x-compatible fashion.


The patch at http://bugs.python.org/issue1029 apparently fixes this problem.