Give all async exceptions in pub some sort of stack trace.

utils/pub/curl_client.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 curl_client;
 
 import 'dart:io';
 
 import '../../pkg/http/lib/http.dart' as http;
 import 'io.dart';
@@ skipping 117 matching lines @@
     // If there's not going to be a response body (e.g. for HEAD requests), curl
     // prints the headers to stdout instead of the body. We want to wait until
     // all the headers are received to read them from the header file.
     if (!expectBody) {
       return Futures.wait([
         consumeInputStream(process.stdout),
         exitFuture
       ]);
     }
 
+    // TODO(nweiz): remove this when issue 4061 is fixed.
+    var stackTrace;
+    try {
+      throw null;

[Bob Nystrom, 2012/11/29 22:25:40]

Throwing null is forbidden and causes a different kind of exception to be
thrown. It doesn't really matter much, but I think it would be slightly less
weird to throw a non-null value. null is the one value in all of Dart that has
special throw semantics. Maybe throw 'dummy';?

[nweiz, 2012/11/29 22:39:02]

Done.

+    } catch (_, localStackTrace) {
+      stackTrace = localStackTrace;
+    }
+
     var completer = new Completer();
     resetCallbacks() {
       process.stdout.onData = null;
       process.stdout.onError = null;
       process.stdout.onClosed = null;
     }
     process.stdout.onData = () {
       // TODO(nweiz): If an error happens after the body data starts being
       // received, it should be piped through Response.stream once issue
       // 3657 is fixed.
       exitFuture.handleException((e) => true);
       resetCallbacks();
       completer.complete(null);
     };
     process.stdout.onError = (e) {
       resetCallbacks();
-      completer.completeException(e);
+      completer.completeException(e, stackTrace);
     };
     process.stdout.onClosed = () {
       resetCallbacks();
       chainToCompleter(exitFuture, completer);
     };
     return completer.future;
   }
 
   /// Returns a [http.StreamedResponse] from the response data printed by the
   /// `curl` [process]. [lines] are the headers that `curl` wrote to a file.
@@ skipping 36 matching lines @@
   /// path to the bundled `curl.exe`; elsewhere, this is just "curl", and we
   /// assume it to be installed and on the user's PATH.
   static String get _defaultExecutable {
     if (Platform.operatingSystem != 'windows') return 'curl';
     // Note: This line of code gets munged by create_sdk.py to be the correct
     // relative path to curl in the SDK.
     var pathToCurl = "../../third_party/curl/curl.exe";
     return relativeToPub(pathToCurl);
   }
 }