diff -u b/core/includes/install.core.inc b/core/includes/install.core.inc
--- b/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -1035,10 +1035,11 @@
   // system.module in order to work.
   file_ensure_htaccess();
 
-  // Before installing the user module, perform a module rebuild so we know
-  // where the user module is located.
+  // Prime the drupal_get_filename() static cache with the user module's
+  // exact location.
   // @todo Remove as part of https://www.drupal.org/node/2186491
-  system_rebuild_module_data();
+  drupal_get_filename('module', 'user', 'core/modules/user/user.info.yml');
+
   // Enable the user module so that sessions can be recorded during the
   // upcoming bootstrap step.
   \Drupal::service('module_installer')->install(array('user'), FALSE);