I kept getting errors uploading to Google App Engine on Mac.
ERROR appcfg.py:1128 An unexpected error occurred. Aborting.
I run as a normal user. Apparently appcfg.py requires some elevated privileges, as running it as root uploaded without a problem.
Here is the command to run the appcfg.py inside the GoogleAppEngineLauncher app.
sudo /Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/appcfg.py update appdirectory/ --noisy -v --email firstname.lastname@example.org
Substitute your own appdirectory and username and path to the GoogleAppEngineLauncher.app.