anchor.diff:  -- Install LuaRocks files
   -- ***********************************************************
   
  -if exists(vars.FULL_PREFIX) then
  +if exists(vars.PREFIX) then
     if not FORCE then
  -    die(S"$FULL_PREFIX exists. Use /F to force removal and reinstallation.")
  +    die(S"$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(S"Removing $PREFIX...")
  +    exec(S[[RD /S /Q "$PREFIX"]])
       print()
     end
   end
   
  -print(S"Installing LuaRocks in $FULL_PREFIX...")
  +print(S"Installing LuaRocks in $PREFIX...")
   if not exists(vars.BINDIR) then
   	if not mkdir(vars.BINDIR) then
   		die()
  
positive.code:     temppath = os.getenv("temp").."\\LR-config-backup-"..tostring(math.random(10000))
      if exists(temppath) then temppath = nil end
    end
    print("'"..temppath.."'")
    vars.CONFBACKUPDIR = temppath
    mkdir(vars.CONFBACKUPDIR)
    exec(S[[COPY "$PREFIX\config*.*" "$CONFBACKUPDIR" >NUL]])
    exec(S[[COPY "$FULL_PREFIX\lua\luarocks\site_config*.*" "$CONFBACKUPDIR" >NUL]])
  end
  
  -- restore previously backed up config files
  local function restore_config_files()
    if not vars.CONFBACKUPDIR then return end -- there is no backup to restore
    exec(S[[COPY "$CONFBACKUPDIR\config*.*" "$PREFIX" >NUL]])
    exec(S[[COPY "$CONFBACKUPDIR\site_config*.*" "$FULL_PREFIX\lua\luarocks" >NUL]])
    -- cleanup
    exec(S[[RD /S /Q "$CONFBACKUPDIR"]])
    vars.CONFBACKUPDIR = nil
  
negative.code:   PATH     :   $LUA_BINDIR
    PATHEXT  :   .LUA
  LuaRocks;
    PATH     :   $PREFIX
    LUA_PATH :   $PREFIX\lua\?.lua;$PREFIX\lua\?\init.lua
  Local user rocktree (Note: %APPDATA% is user dependent);
    PATH     :   %APPDATA%\LuaRocks\bin
    LUA_PATH :   %APPDATA%\LuaRocks\share\lua\$LUA_VERSION\?.lua;%APPDATA%\LuaRocks\share\lua\$LUA_VERSION\?\init.lua
  