I use org-mode to publish my web site that I update every now and then. The site contains my lectures, and indeed I am preparing my lecture for tomorrow. Unfortunately, while publishing the site using the usual procedure, I get the infamous error

    Symbol's value as variable is void: overlays

For publishing, I run emacs in batch mode from a makefile as follows:

    emacs --batch -l batch_project.el --kill

and my batch_project.el is attached. I cannot attach a minimal file that produces the error, because I find it difficult to come up with a minimal example. All I can say is that the error is produced after many .org files have been correctly processed.  Everything used to work until a few months ago. Last week I switched to the latest version of emacs from the git repo, and today I get the error. Maybe I should clean some cache? Or change the configuration of the project?

Can someone suggest me any direction where I should look into?

Thanks in advance

Giuseppe Lipari