I try to install elgg-3.1.2/elgg-3.1.3 using HHVM

hello,

i try to install elgg 3* using HHVM.. in that installation of first step i get error everytime like :

 \nFatal error: Default value for parameter leave_base_directory with a class type hint can only be NULL in /usr/local/nginx/html/elgg-3.1.2/vendor/elgg/elgg/engine/lib/filestore.php on line 80