Why can't I delete my app's folder in the "tmp0" folder?

Eclipse seems to be deploying my app to:

When and how does this happen? When I deleted “MyProject” folder from that location, I expected the app to be re-created when I build or run my project.

But that folder is only partially re-created. This folder is found:
…/MyProject/WEB-INF/classes/com.mystuff… (My own Vaadin app’s classes are there)
But missing in action are:

How can I get Eclipse to re-deploy that app?

Not positive, but rather than delete the webapp code, you should consider stopping any debugging and remove the file YOURPOJECTROOT/.metadata/.plugins/org.eclipse.wst.server.core/publish/publish0.dat. Seems like when you restart debugging, this causes the webapps to be republished in full.

Yes, deleting the “publish0.dat” file seems to succeed in forcing a rebuild of the deployment folder in “tmp0” folder. But only if I quit and restart Eclipse.

Thank you.