screen: Debug

 
 20.6 Debug
 ==========
 
  -- Command: debug [on|off]
      (none)
      Turns runtime debugging on or off.  If 'screen' has been compiled
      with option '-DDEBUG' debugging is available and is turned on per
      default.  Note that this command only affects debugging output from
      the main 'SCREEN' process correctly.  Debug output from attacher
      processes can only be turned off once and forever.