wjh…@gmail.com has answered to the question on the Google (code) Appengine website
(1) Move the AppEngineLauncher icon to /Applications
(2) Open a Terminal Window and ‘cd /Applications’
(3) Run ‘sudo open GoogleAppEngineLauncher.app’
You’ll be promoted for your admin password later to make the symlinks but that seems to have done it for the installer.
Starting a new project using Python on the Google App Engine, I decided to keep in mind the steps put in place in order to make this project running.
Due to this, I have created a list of resources that should help you out if you want to achieve the same goal.
Create a new project: http://code.google.com/hosting/createProject
Create a new group: http://groups.google.com/groups/create
Mercurial source control
Quickstart to mercurial http://mercurial.selenic.com/quickstart/
Quick reference card and cheat sheets: http://mercurial.selenic.com/wiki/QuickReferenceCardsAndCheatSheets
Mercurial source control: http://mercurial.selenic.com/downloads/
Eclipse IDE: http://www.eclipse.org/downloads/
Google Plugin for Eclipse: http://code.google.com/eclipse/docs/getting_started.html
Mercurial plugin for Eclipse: http://code.google.com/a/eclipselabs.org/p/mercurialeclipse/
MercurialEclipse and its priceless tips http://www.javaforge.com/project/HGE
Create the new repository – watch this tutorial : http://www.javaforge.com/wiki/78696
Gnu Privacy Gard (GnuPG) tools : http://www.gnupg.org/