phorge-phorge/resources/sql/patches/20130611.nukeldap.php

<?php

$table = new PhabricatorUser();
$conn = $table->establishConnection('w');
$table_name = 'user_ldapinfo';

foreach (new LiskRawMigrationIterator($conn, $table_name) as $row) {
  throw new Exception(
    pht(
      'Your Phabricator install has ancient LDAP account data and is '.
      'too old to upgrade directly to a modern version of Phabricator. '.
      'Upgrade to a version released between June 2013 and February 2019 '.
      'first, then upgrade to a modern version.'));
}