Improve pylint error message with an old version is used.

Instead of crashing, prints an error message.

BUG=
TEST=


Review URL: http://codereview.chromium.org/8363030

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@106867 0039d316-1c4b-4281-b951-d872f2087c98

presubmit_canned_checks.py

@@ -634,6 +634,7 @@ def RunPylint(input_api, output_api, white_list=None, black_list=None):
     # were listed, try to run pylint.
     try:
       from pylint import lint
+      from pylint.utils import UnknownMessage
       input_api.logging.debug(
           'Using pylint v%s from %s' % (lint.version, lint.__file__))
     except ImportError:
@@ -655,6 +656,8 @@ def RunPylint(input_api, output_api, white_list=None, black_list=None):
       except SystemExit, e:
         # pylint has the bad habit of calling sys.exit(), trap it here.
         return e.code
+      except UnknownMessage, e:
+        return 'Please upgrade pylint: %s' % e
 
     result = None
     if not input_api.verbose:
@@ -662,10 +665,10 @@ def RunPylint(input_api, output_api, white_list=None, black_list=None):
     else:
       for filename in sorted(files):
         print('Running pylint on %s' % filename)
-        out = run_lint([filename])
-        if out:
-          result = out
-    if result:
+        result = run_lint([filename]) or result
+    if isinstance(result, basestring):
+      return [error_type(result)]
+    elif result:
       return [error_type('Fix pylint errors first.')]
     return []
   finally:

pylintrc

@@ -35,6 +35,7 @@ load-plugins=
 # C0103: Invalid name ""
 # C0111: Missing docstring
 # C0302: Too many lines in module (N)
+# I0010: Unable to consider inline option ''
 # I0011: Locally disabling WNNNN
 #
 # It's a problem but not something we can fix right now.
@@ -62,7 +63,7 @@ load-plugins=
 # W0613: Unused argument ''
 # W0703: Catch "Exception"
 # W1201: Specify string format arguments as logging function parameters
-disable=C0103,C0111,C0302,I0011,R0401,R0801,R0901,R0902,R0903,R0904,R0911,R0912,R0913,R0914,R0915,R0921,R0922,W0122,W0141,W0142,W0402,W0404,W0511,W0603,W0613,W0703,W1201
+disable=C0103,C0111,C0302,I0010,I0011,R0401,R0801,R0901,R0902,R0903,R0904,R0911,R0912,R0913,R0914,R0915,R0921,R0922,W0122,W0141,W0142,W0402,W0404,W0511,W0603,W0613,W0703,W1201
 
 
 [REPORTS]