The difference with $Data::Dumper::Useperl = 1; is related to strings that can be represented entirely without utf8. On ingest eval makes the usual perl heuristic about utf8, and gets it wrong: 
#!/usr/bin/perl -w
use utf8;       # so source code is utf-8 encoded
use Data::Dumper;

$data1 = 'ä ☺'; # a-umlaut, space, smiley
$data2 = 'ä  '; # a-umlaut, space, space

$Data::Dumper::Useperl = 1;
$dump1 = Dumper( $data1 );
print $dump1;
$dump2 = Dumper( $data2 );
print $dump2;
print "\n";

$Data::Dumper::Useperl = 0;
$dump1 = Dumper( $data1 );
print $dump1;
$dump2 = Dumper( $data2 );
print $dump2;
print "\n";

[download]

Output 

$VAR1 = "\x{e4} \x{263a}";
$VAR1 = 'ä  ';

$VAR1 = "\x{e4} \x{263a}";
$VAR1 = "\x{e4}  ";

[download]

In reply to Re: Data::Dumper and utf8 by brycen
in thread Data::Dumper and utf8 by thedi

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