Index: tools/hook-scripts/mailer/mailer.py
===================================================================
--- tools/hook-scripts/mailer/mailer.py	(revision 21923)
+++ tools/hook-scripts/mailer/mailer.py	(working copy)
@@ -22,7 +22,7 @@
 #   if the property was added, modified or deleted, respectively.
 #
 #   This version of mailer.py requires the python bindings from
-#   subversion 1.2.0 or later.
+#   subversion 1.5.0 or later.
 #
 
 import os
@@ -38,14 +38,32 @@
 import types
 import urllib
 
-import svn.fs
-import svn.delta
-import svn.repos
-import svn.core
+# Minimal version of Subversion's bindings required
+_MIN_VERSION = [1, 5, 0]
 
+# Import the Subversion Python bindings, making sure they meet our
+# minimum version requirements.
+try:
+  import svn.fs
+  import svn.delta
+  import svn.repos
+  import svn.core
+except ImportError:
+  sys.stderr.write(
+    "You need version %s or better of the Subversion Python bindings.\n" \
+    % string.join(map(lambda x: str(x), _MIN_VERSION), '.'))
+  sys.exit(1)
+if _MIN_VERSION > [svn.core.SVN_VER_MAJOR,
+                   svn.core.SVN_VER_MINOR,
+                   svn.core.SVN_VER_PATCH]:
+  sys.stderr.write(
+    "You need version %s or better of the Subversion Python bindings.\n" \
+    % string.join(map(lambda x: str(x), _MIN_VERSION), '.'))
+  sys.exit(1)
+
+
 SEPARATOR = '=' * 78
 
-
 def main(pool, cmd, config_fname, repos_dir, cmd_args):
   ### TODO:  Sanity check the incoming args