Eclipse & Google App Engine – Variable references empty selection: ${project_loc}

If, when you try to debug or run a PyDev Google app engine project in eclipse after following these instructions, you may experience this error message:

Variable references empty selection: ${project_loc}

If you get this error you should be able to make it go away by first clicking on you project in the PyDev package explorer window before trying to debug or run your project. Eclipse & PyDev can be just a little quirky…