Wide character in %s

(W utf8) Perl met a wide character (>255) when it wasn't expecting one. This warning is by default on for I/O (like print). The easiest way to quiet this warning is simply to add the :utf8 layer to the output, e.g. binmode STDOUT, ':utf8'. Another way to turn off the warning is to add no warnings 'utf8'; but that is often closer to cheating. In general, you are supposed to explicitly mark the filehandle with an encoding, see the open manpage and binmode in the perlfunc manpage.