Put a nasty sleep() on Windows.

utils/pub/io.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.
 
 /**
  * Helper functionality to make working with IO easier.
  */
 library io;
 
 import 'dart:io';
@@ skipping 667 matching lines @@
   // relative path to 7zip in the SDK.
   var pathTo7zip = '../../third_party/7zip/7za.exe';
   var command = scriptDir.append(pathTo7zip).canonicalize().toNativePath();
 
   var tempDir;
 
   return createTempDir().chain((temp) {
     // Write the archive to a temp file.
     tempDir = temp;
     return createFileFromStream(stream, join(tempDir, 'data.tar.gz'));
-  }).chain((tarGz) {
+  }).chain((_) {
+    // TODO(rnystrom): Hack. We get intermittent "file already in use" errors.

[kasperl, 2012/10/16 05:44:46]

This smells like a dart:io issue. Did you file a bug report already?

+    // It looks like the 7zip process is starting up before the file has
+    // finished being written. So we'll just sleep for a couple of seconds
+    // here. :(
+    return sleep(2000);
+  }).chain((_) {
     // 7zip can't unarchive from gzip -> tar -> destination all in one step
     // first we un-gzip it to a tar file.
     // Note: Setting the working directory instead of passing in a full file
     // path because 7zip says "A full path is not allowed here."
     return runProcess(command, ['e', 'data.tar.gz'], workingDir: tempDir);
   }).chain((result) {
     if (result.exitCode != 0) {
       throw 'Could not un-gzip (exit code ${result.exitCode}). Error:\n'
           '${Strings.join(result.stdout, "\n")}\n'
           '${Strings.join(result.stderr, "\n")}';
     }
-
     // Find the tar file we just created since we don't know its name.
     return listDir(tempDir);
   }).chain((files) {
     var tarFile;
     for (var file in files) {
       if (new Path(file).extension == 'tar') {
         tarFile = file;
         break;
       }
     }
 
     if (tarFile == null) throw 'The gzip file did not contain a tar file.';
 
     // Untar the archive into the destination directory.
     return runProcess(command, ['x', '-o"$destination"', tarFile],
         workingDir: tempDir);
   }).chain((result) {
     if (result.exitCode != 0) {
       throw 'Could not un-tar (exit code ${result.exitCode}). Error:\n'
+          '${Strings.join(result.stdout, "\n")}\n'
           '${Strings.join(result.stderr, "\n")}';
     }
 
     // Clean up the temp directory.
     // TODO(rnystrom): Should also delete this if anything fails.
     return deleteDir(tempDir);
   }).transform((_) => true);
 }
 
 /**
@@ skipping 49 matching lines @@
   return new Directory(entry);
 }
 
 /**
  * Gets a [Uri] for [uri], which can either already be one, or be a [String].
  */
 Uri _getUri(uri) {
   if (uri is Uri) return uri;
   return new Uri.fromString(uri);
 }