Changing port for Google App Engine while using grails

The context

I am using Google App Engine using the  Grails AppEngine plugin . The default port is 8080, but I needed to run it on a different port.

It was easy to figure out that Google App Engine supports running the development server on any configured port. But it took me some time to realize that [...]

Error: Appengine is already registered

The context:

I am using Google App Engine along with Grails AppEngine plugin. At some point I started getting an exception when I was trying to start my development server. The only thing I had done before I got the error was- I had switched from App Engine SDK  1.2.5 to 1.2.8.

The solution

The problem is that [...]

The site says xdb

Its not always your site says anything to you

But mine did…It said ‘XDB’.

It was my grails application.This is the login window Firefox showed be gleefully with the message

The site says XDB

IE played dumb(er) - It too presented a login screen - but had a simpler message

XDB

I was in the process of trying a few things [...]