Huh? In your snippet, perl is "just printing whatever gets thrown at it", without doing any sort of "translation" on it.

It's trying and failing to convert Unicode code point 0x263a to Latin-1. We see the warning because it's impossible to translate a code point that high to Latin 1.

I thought the example I gave was the easiest to grok, but this is probably better, because the output is actually different.

#!/usr/bin/perl
use strict;
use warnings;

use Encode qw( _utf8_on );

my $resume = "r\xc3\xa9sum\xc3\xa9";
print $resume, "\n";

_utf8_on($resume);

print $resume, "\n";
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Conceptually, appending a non-UTF8 string to a UTF8 string is a really bad idea, bordering on stupid. Don't do that. (Why would you want to? What would you hope to accomplish as a result?)

I'd like to spit out scalars flagged as UTF8 by default from KinoSearch. But if I do that, that means anybody who gets that output is going to have to know how to deal with them. I don't want to spend all my time explaining the bottomless intricacies of Unicode handling in Perl to people. It's not that I want to be doing a lot of this concatenation, it's that I know it's going to happen some of the time and I don't want the support burden.