Better error message when trying to use -R on an unknown module.
Better error message when trying to use -R on an unknown module.

norton/chibi-scheme,holmescn/chibi-scheme,norton/chibi-scheme,norton/chibi-scheme,norton/chibi-scheme,holmescn/chibi-scheme,norton/chibi-scheme,holmescn/chibi-scheme,holmescn/chibi-scheme,norton/chibi-scheme,holmescn/chibi-scheme