issue-29177-02.diff is a modified version of the previous patch that uses support.unlink() instead of os.remove() to handle the failure occuring for a non-existent file
when the test is skipped because of Permission denied. With this patch test_logging is ok, and test_lib2to3 runs fine after test_logging.

issue-29177-03.patch adds the following modifications to the previous patches:
  * Catch only OSError: it is better not to catch programming errors as they may go unnoticed when the test is skipped.
  * Report the OSError in the skip message.
  * Reduce the scope of the try clause to just the code that uses system calls.
  * The cleanup done in setUp() by the previous patch in the except clause does not seem to be needed as the tearDown() method is invoked when the test is skipped.