anchor.diff:  -- ***********************************************************
   -- Install LuaRocks files
   -- ***********************************************************
  -if FORCE then
  -	print(S"Removing $FULL_PREFIX...")
  -	exec(S[[RD /S /Q "$FULL_PREFIX"]])
  -	print()
  -end
   
   if exists(vars.FULL_PREFIX) then
  -	die(S"$FULL_PREFIX exists. Use /F to force removal and reinstallation.")
  +  if not FORCE then
  +    die(S"$FULL_PREFIX exists. Use /F to force removal and reinstallation.")
  +  else
  +    backup_config_files()
  +    print(S"Removing $FULL_PREFIX...")
  +    exec(S[[RD /S /Q "$FULL_PREFIX"]])
  +    print()
  +  end
   end
   
   print(S"Installing LuaRocks in $FULL_PREFIX...")
  
positive.code: vars.PREFIX = nil
  vars.VERSION = "2.2"
  vars.SYSCONFDIR = nil
  vars.SYSCONFFILENAME = nil
  vars.CONFIG_FILE = nil
  vars.TREE_ROOT = nil
  
negative.code: 
  local function exec(cmd)
  	--print(cmd)
  	local status = os.execute("type NUL && "..cmd)
  	return (status == 0 or status == true) -- compat 5.1/5.2
  end
  
  