Make use of shadow utils conditional on config

mock/py/mockbuild/shadow_utils.py

@@ -22,7 +22,11 @@ def _execute_command(self, command, can_fail=False):
         with self.root.uid_manager.elevated_privileges():
             # Execute the command in bootstrap, since host configuration may not permit
             # ordinary user addition, such as would happen with freeipa-provided subids
-            do_with_status(command, chrootPath=self.chroot_dir, raiseExc=not can_fail)
+            if ('use_chroot_shadow_utils' in self.root.config) and self.root.config['use_chroot_shadow_utils']:
+                do_with_status(command, chrootPath=self.chroot_dir, raiseExc=not can_fail)
+            else:
+                do_with_status(command + ['--prefix', self.chroot_dir], raiseExc=not can_fail)
+
 
     def delete_user(self, username, can_fail=False):
         """