add local assertRaisesRegexp() on python older then 2.7

When running tests on python older then 2.7, monkeypatch
unittest.TestCase class to include assertRaisesRegexp() method.

slave/buildslave/monkeypatches/__init__.py

@@ -34,5 +34,16 @@ def patch_bug5079():
         from buildslave.monkeypatches import bug5079
         bug5079.patch()
 
-def patch_all():
+def patch_testcase_assert_raises_regexp():
+    # pythons before 2.7 does not have TestCase.assertRaisesRegexp() method
+    # add our local implementation if needed
+    import sys
+    if sys.version_info[:2] < (2,7):
+        from buildslave.monkeypatches import testcase_assert
+        testcase_assert.patch()
+
+def patch_all(for_tests=False):
     patch_bug4881()
+
+    if for_tests:
+        patch_testcase_assert_raises_regexp()

slave/buildslave/monkeypatches/testcase_assert.py

@@ -0,0 +1,48 @@
+# This file is part of Buildbot.  Buildbot is free software: you can
+# redistribute it and/or modify it under the terms of the GNU General Public
+# License as published by the Free Software Foundation, version 2.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc., 51
+# Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# Copyright Buildbot Team Members
+
+
+import re
+import unittest
+
+
+def _assertRaisesRegexp(self, expected_exception, expected_regexp,
+                        callable_obj, *args, **kwds):
+    """
+    Asserts that the message in a raised exception matches a regexp.
+
+    This is a simple clone of unittest.TestCase.assertRaisesRegexp() method
+    introduced in python 2.7. The goal for this function is to behave exactly
+    as assertRaisesRegexp() in standard library.
+    """
+    exception = None
+    try:
+        callable_obj(*args, **kwds)
+    except expected_exception, ex:  # let unexpected exceptions pass through
+        exception = ex
+
+    if exception == None:
+        self.fail("%s not raised" % str(expected_exception.__name__))
+
+    if isinstance(expected_regexp, basestring):
+        expected_regexp = re.compile(expected_regexp)
+
+    if not expected_regexp.search(str(exception)):
+        self.fail('"%s" does not match "%s"' %
+                     (expected_regexp.pattern, str(exception)))
+
+
+def patch():
+    unittest.TestCase.assertRaisesRegexp = _assertRaisesRegexp

slave/buildslave/test/__init__.py

@@ -20,7 +20,7 @@
 from buildslave import monkeypatches
 
 # apply the same patches the slave does when it starts
-monkeypatches.patch_all()
+monkeypatches.patch_all(for_tests=True)
 
 def add_debugging_monkeypatches():
     """