centralized ensure dir

internal/engine.cm

@@ -1466,20 +1466,12 @@ $_.clock(_ => {
       if (!fd.is_dir(_dep_dir)) {
         log.console('installing missing dependency: ' + _deps[_di])
         _auto_install = function() {
-          shop.update(_deps[_di])
-          shop.fetch(_deps[_di])
-          shop.extract(_deps[_di])
-          shop.build_package_scripts(_deps[_di])
+          shop.sync(_deps[_di])
         } disruption {
           log.error('failed to install dependency: ' + _deps[_di])
           disrupt
         }
         _auto_install()
-        _dep_dir = package.get_dir(_deps[_di])
-        if (!fd.is_dir(_dep_dir)) {
-          log.error('missing dependency package: ' + _deps[_di])
-          disrupt
-        }
       }
       _di = _di + 1
     }