Create destination directory before git cloning into it.

utils/pub/git_source.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('git_source');
 
 #import('io.dart');
 #import('package.dart');
 #import('source.dart');
 #import('source_registry.dart');
@@ skipping 135 matching lines @@
   }
 
   /**
    * Clones the repo at the URI [from] to the path [to] on the local filesystem.
    *
    * If [mirror] is true, create a bare, mirrored clone. This doesn't check out
    * the working tree, but instead makes the repository a local mirror of the
    * remote repository. See the manpage for `git clone` for more information.
    */
   Future _clone(String from, String to, [bool mirror=false]) {
-    var args = ["clone", from, to];
-    if (mirror) args.insertRange(1, 1, "--mirror");
-    return runGit(args).transform((result) {
+    // Git on Windows does not seem to automatically create the destination
+    // directory.
+    return ensureDir(to).chain((_) {
+      var args = ["clone", from, to];
+      if (mirror) args.insertRange(1, 1, "--mirror");
+      return runGit(args);
+    }).transform((result) {
       if (!result.success) throw 'Git failed.';
       return null;
     });
   }
 
   /**
    * Checks out the reference [ref] in [repoPath].
    */
   Future _checkOut(String repoPath, String ref) {
     return runGit(["checkout", ref], workingDir: repoPath).transform((result) {
@@ skipping 54 matching lines @@
 
   /**
    * Returns [description] if it's a description, or [PackageId.description] if
    * it's a [PackageId].
    */
   _getDescription(description) {
     if (description is PackageId) return description.description;
     return description;
   }
 }