Okay, fixed my own code. This works with 5.8.4:

use Tk;
use strict;
use warnings;

my $main = new MainWindow();
my $canvas = $main->Scrolled('Canvas',
                              -scrollregion => [0,0,1000,500],
)->pack(-fill=>"both");
$canvas->createOval(100,100,500,500);

MainLoop;
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