rakudo pod parsing slowness when '=end pod' is missing

slooow.p6

use v6;

sub timeit(Int $lines-after) {
    my $preamble = qq[=begin code\n];
    my $str = join "\n", $preamble, "Some more happy, happy lines of B<pod>\n\n   including code\n\n" xx $lines-after;

    my $before = now;
    try EVAL qq[=begin pod\n\n$str\n\n\=end pod\n"];
    my $after = now;
    return $after - $before;

}

for ^50 -> $t {
    given $t * 1 {
        say join "\t", $_, timeit($_);
    }
}

# output:
#
# 0       0.010546
# 1       0.0218128
# 2       0.10669325
# 3       0.7040623
# 4       5.6502557
# 5       45.8098792
# (here I lost patience)