Perl Encode.pm cannot decode string with wide character

Question

I was running a perl app which uses /opt/local/lib/perl5/5.12.4/darwin-thread-multi-2level/Encode.pm

and issues an error

Cannot deco

Answer 1

encode takes a string of Unicode code points and serialises them into a string of bytes.

decode takes a string of bytes and deserialises them into Unicode code points.

That message means you passed a string containing one or more characters above 255 (non-bytes) to decode, which is obviously an incorrect argument.

>perl -MEncode -E"for (254..257) { say; decode('iso-8859-1', chr($_)); }"
254
255
256
Wide character in subroutine entry at .../Encode.pm line 176.

You ask for a workaround, but the bug is yours. Perhaps you are accidentally trying to decode something you already decoded?