drush @devextranet-aegir.local cr

In Database.php line 361:
                                                             
  The specified database connection is not defined: default  
                                                             

cache:rebuild [--cache-clear [CACHE-CLEAR]] [--no-cache-clear] [-h|--help] [-q|--quiet] [-v|vv|vvv|--verbose] [-V|--version] [--ansi] [--no-ansi] [-n|--no-interaction] [-d|--debug] [-y|--yes] [--no] [--remote-host REMOTE-HOST] [--remote-user REMOTE-USER] [-r|--root ROOT] [-l|--uri URI] [--simulate] [--pipe] [-D|--define DEFINE] [--druplicon] [--notify [NOTIFY]] [--xh-link XH-LINK] [--] <command>