I'd have to go with bug as the following works..

#!/usr/bin/perl -T
use strict;
use warnings;
$ENV{PATH} = '/usr/bin:/usr/local/bin:/bin';
$ENV{ENV} = '';

sub do_nothing {  @_; }


my $vars =  [ 
              do_nothing( `echo "base"`),  
              do_nothing(`echo "BAR"`),
            ];
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