Ensure the packages directory exists.

dart/tools/make_links.py

 #!/usr/bin/env python
 # 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.
 
 
 '''Tool for creating symlinks from SOURCES to TARGET.
 
 For each SOURCE in SOURCES create a link from SOURCE to TARGET.  If a
 SOURCE ends with .../lib, the lib suffix is ignored when determining
@@ skipping 32 matching lines @@
   sys.stdout.flush()
 
   if utils.GuessOS() == 'win32':
     return subprocess.call(['mklink', '/j', target, source], shell=True)
   else:
     return subprocess.call(['ln', '-s', source, target])
 
 
 def main(argv):
   target = os.path.relpath(argv[1])
+  if not os.path.exists(target):
+    os.makedirs(target)
   for source in argv[2:]:
-    # Assume the source directory is named ".../TARGET_NAME/lib".
+    # Assume the source directory is named ".../NAME/lib".
     (name, lib) = os.path.split(source)
     if lib != 'lib':
       name = source
-    # Remove any addtional path components preceding TARGET_NAME.
+    # Remove any addtional path components preceding NAME.
     (path, name) = os.path.split(name)
     if utils.GuessOS() == 'win32':
       source = os.path.relpath(source)
     else:
       source = os.path.relpath(source, start=target)
     exit_code = make_link(source, os.path.join(target, name))
     if exit_code != 0:
       return exit_code
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))