Make the CheckTreeIsOpen presubmit check fail on IOError.

presubmit_canned_checks.py

Index: presubmit_canned_checks.py
===================================================================
--- presubmit_canned_checks.py	(revision 119723)
+++ presubmit_canned_checks.py	(working copy)
@@ -458,8 +458,10 @@
         long_text = status + '\n' + url
         return [output_api.PresubmitError('The tree is closed.',
                                           long_text=long_text)]
-  except IOError:
-    pass
+  except IOError as e:
+    short_text = 'Error fetching tree status.'
+    long_text = str(e)
+    return [output_api.PresubmitError(short_text, long_text=long_text)]

[M-A Ruel, 2012/01/30 20:50:15]

I don't see much value in the 2 named variables. Just put the value directly as
argument to PresubmitError().

[rohitrao (ping after 24h), 2012/01/30 20:58:54]

Done.

   return []