Go to http://fr.m.wikipedia.org/wiki/Wikip%C3%A9dia:Accueil%20principal?title=Wikip%C3%A9dia:Accueil_principal&mobileaction=toggle_view_mobile in beta mode
Open console
I get the error ""Uncaught ReferenceError: wgPageContentLanguage is not defined"
Version: unspecified
Severity: enhancement
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=44070