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

BUG=
R=kustermann@google.com

Review URL: https://codereview.chromium.org//19792005

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@25220 260f80e4-7a28-3924-810f-c04153c831b5

lib/src/source/hosted.dart

@@ -167,7 +167,7 @@ class HostedSource extends Source {
 
     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.