"empty slug for" should be "empty title for"

[kylef]

WARNING: empty slug for 'content/pages/about.rst

This happens when you leave a title out of the page. Since the code makes a slug from the title if there isn't already one.

[almet]

Well, the problem is that pelican doesn't find a slug, the fact that there isn't any title is not really a problem, since it can be omitted and you can refer to articles / pages just using their slugs.

However, the slug is mandatory, thus the error message. Maybe can we do something a bit more clearer for the end user, adding: "You can resolve this by adding a title or a slug to your content".

Would it be sufficient?