Unable to use mvn gae:run with version maven-gae-plugin:0.9.4?

I am using maven gae plugin version 0.9.4 and whenever I use mvn gae:run I get the following error:

Usage: <dev-appserver> [options] <war directory>

Options:
 --help, -h                 Show this help message and exit.
 --server=SERVER            The server to use to determine the latest
  -s SERVER                   SDK version.
 --address=ADDRESS          The address of the interface on the local machine
  -a ADDRESS                  to bind to (or 0.0.0.0 for all interfaces).
 --port=PORT                The port number to bind to on the local machine.
  -p PORT
 --sdk_root=root            Overrides where the SDK is located.
 --disable_update_check     Disable the check for newer SDK versions.
 --generated_dir=dir        Set the directory where generated files are created.

Googling this turned up some old threads where this used to be a problem in 0.5 versions of the plugin but was fixed. Not sure why its happening for me and what are the work arrounds. Any ideas?

Solution

I also experienced this problem with maven-gae-plugin 0.9.4 and jdk1.6.0_23 on Windows 7. All I did to reproduce this was to create a project using the gae-archetype-jsp archetype and then use mvn gae:run.

However, I backed maven-gae-plugin down to 0.9.2 and the problem went away!