the value of the gae.home property should be the absolute path of your GAE installation on your local machine. You have to put that property either in the USER_HOME/.m2/settings.xml (globally) or in your project’s pom.xml. Check out http://www.sonatype.com/books/mvnref-book/reference/resource-filtering.html and http://blog.cloudme.org/2010/04/mavenizing-my-project/ as an example.

However, the latest releases of the GAE plugin have a very nice feature, which makes setting the gae.home property obsolete: with gae:unpack you can install GAE in your local Maven repository, no property settings required.

Could you please tell how you set up the gae.home property?
What value do you put?

thank you
Ludovic