Who or what restarts the tasks?

I'm not sure at which point should the directory be deleted, because there is no restarting logic in pungi itself. It just starts it and waits for it to finish. Each compose uses its own buildinstall work directory, so that should create no conflicts either.

There is this thing in pungi: before starting the task, it checks if the output directory exists. If it is an empty dir, it gets removed. If it is non empty, the task is not started (this is meant to allow composes to be redone in debug mode). This code is a little broken for lorax path, as it uses slightly different paths than original buildinstall. Patch in PR #368.