Stop working around issue 7781 in Pub.

utils/pub/pub.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.
 
 /// The main entrypoint for the pub command line application.
 library pub;
 
 import 'dart:async';
 import '../../pkg/args/lib/args.dart';
 import '../../pkg/path/lib/path.dart' as path;
@@ skipping 244 matching lines @@
       } catch (error, trace) {
         handleError(error, trace);
         return new Future.immediate(null);
       }
     });
 
 
     future
       .then((_) => cache_.deleteTempDir())
       .catchError((asyncError) {
-        var e = getRealError(asyncError);
+        var e = asyncError.error;
         if (e is PubspecNotFoundException && e.name == null) {
           e = 'Could not find a file named "pubspec.yaml" in the directory '
             '${path.current}.';
         } else if (e is PubspecHasNoNameException && e.name == null) {
           e = 'pubspec.yaml is missing the required "name" field (e.g. "name: '
             '${basename(path.current)}").';
         }
 
-        handleError(e, getRealStackTrace(asyncError));
+        handleError(e, asyncError.stackTrace);
       })
       // Explicitly exit on success to ensure that any dangling dart:io handles
       // don't cause the process to never terminate.
       .then((_) => exit(0));
   }
 
   /// Override this to perform the specific command. Return a future that
   /// completes when the command is done or fails if the command fails. If the
   /// command is synchronous, it may return `null`.
   Future onRun();
@@ skipping 20 matching lines @@
     if (exception is HttpException || exception is HttpParserException ||
         exception is SocketIOException || exception is PubHttpException) {
       return exit_codes.UNAVAILABLE;
     } else if (exception is FormatException) {
       return exit_codes.DATA;
     } else {
       return 1;
     }
   }
 }