Show repr(value) to improve readability of error message

supervisor/datatypes.py

@@ -384,7 +384,7 @@ def url(value):
     scheme, netloc, path, params, query, fragment = urlparse.urlparse(uri)
     if scheme and (netloc or path):
         return value
-    raise ValueError("value %s is not a URL" % value)
+    raise ValueError("value %r is not a URL" % value)
 
 # all valid signal numbers
 SIGNUMS = [ getattr(signal, k) for k in dir(signal) if k.startswith('SIG') ]
@@ -398,9 +398,9 @@ def signal_number(value):
             name = 'SIG' + name
         num = getattr(signal, name, None)
         if num is None:
-            raise ValueError('value %s is not a valid signal name' % value)
+            raise ValueError('value %r is not a valid signal name' % value)
     if num not in SIGNUMS:
-        raise ValueError('value %s is not a valid signal number' % value)
+        raise ValueError('value %r is not a valid signal number' % value)
     return num
 
 class RestartWhenExitUnexpected:

supervisor/tests/test_datatypes.py

@@ -702,7 +702,7 @@ class SignalNumberTests(unittest.TestCase):
             self._callFUT('12345678')
             self.fail()
         except ValueError as e:
-            expected = "value 12345678 is not a valid signal number"
+            expected = "value '12345678' is not a valid signal number"
             self.assertEqual(e.args[0], expected)
 
     def test_raises_for_bad_name(self):
@@ -710,7 +710,7 @@ class SignalNumberTests(unittest.TestCase):
             self._callFUT('BADSIG')
             self.fail()
         except ValueError as e:
-            expected = "value BADSIG is not a valid signal name"
+            expected = "value 'BADSIG' is not a valid signal name"
             self.assertEqual(e.args[0], expected)
 
 class AutoRestartTests(unittest.TestCase):