Wikimedia Bugzilla is closed!

hhvm does not load all of MediaWiki's context.  For example wfExpandUrl (a global function defined in GlobalFunctions.php) does not work.  This applies both when called indirectly, e.g.:

@var_export( ResourceLoaderFileModule::extractBasePaths() )

and when called directly:

@var_export( wfExpandUrl( '/' ) );