On Beta (example article), the “Add links” sidebar portlet fails with “An unknown error occurred.” WikibaseClient only produces this message in one place, as the failure case for an mw.loader.using call:
wikibase.client.linkitem.init.js
mw.loader.using( [ 'jquery.wikibase.linkitem', 'mediawiki.Title', 'mw.config.values.wbRepo' ], function () { // ... }, function () { // Failure: This isn't very likely, but who knows $spinner.remove(); $linkItemLink.show(); mw.notify( mw.msg( 'unknown-error' ) ); } );
This doesn’t show any error details, but we can reveal them with a similar function call in dev tools:
mw.loader.using( [ 'jquery.wikibase.linkitem', 'mediawiki.Title', 'mw.config.values.wbRepo' ], console.log, console.error );
And this prints:
Error: "Unknown module: util.inherit"