Luggage_isu 3.6.4-6.4 has been released (along with its upstream, Luggage 3.6.4).
Update Drupal 7.63. Drupal 7.62 introduced a regression that affected particular installations of Drush. Details can be found with the Drupal release notes https://www.drupal.org/project/drupal/releases/7.63
A full list of changes to Luggage_isu can be found in LUGGAGE_ISU_CHANGELOG.txt
The release is available at https://github.com/isubit/luggage_isu/releases/tag/6.4
A full list of changes to Luggage can be found in LUGGAGE_CHANGELOG.txt
The release is available at https://github.com/isubit/luggage/releases/tag/3.6.4