Print entire SocketException in pub, to help debug the problem.

sdk/lib/_internal/pub/lib/src/source/hosted.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library pub.source.hosted;
 
 import 'dart:async';
 import 'dart:io' as io;
 import 'dart:json' as json;
 
@@ skipping 149 matching lines @@
         error.response.statusCode == 404) {
       fail('Could not find package "$package" at $url.');
     }
 
     if (error is TimeoutException) {
       fail('Timed out trying to find package "$package" at $url.');
     }
 
     if (error is io.SocketException) {
       fail('Got socket error trying to find package "$package" at $url.\n'
-          '${error.osError}');
+          '$error');
     }
 
     // Otherwise re-throw the original exception.
     throw error;
   }
 }
 
 /// This is the modified hosted source used when pub install or update are run
 /// with "--offline". This uses the system cache to get the list of available
 /// packages and does no network access.
@@ skipping 81 matching lines @@
   var name = description["name"];
   if (name is! String) {
     throw new FormatException("The 'name' key must have a string value.");
   }
 
   var url = description["url"];
   if (url == null) url = HostedSource.defaultUrl;
 
   return new Pair<String, String>(name, url);
 }