Text xslate undefined function with virtual templates

gistfile1.pl

package main;

use Data::Dumper;
use Text::Xslate;

my $count = 0;
my $macro = undef;
my $xslate = Text::Xslate->new(
    path => {
        'test.tx' => qq{
: capture(-> {
Rendering <: count() :>
: })
: render()
}
    },
    cache => 1,
    function => {
        count => sub {
            ++$count;
        },
        capture => sub {
            $macro = bless { macro => shift }, 'test';
            undef;
        },
        render => sub {
            $macro->{macro}->();
        }
    }
);

# works with cache 0/1/2
print $xslate->render('test.tx');
# works with cache 0, undefined function with cache 1/2
print $xslate->render('test.tx');
# works with cache 0, also undefined function with cache 1/2
print $xslate->render('test.tx');