Does that complain under strict? I tried the following:

use strict;

my $foo = 0;
sub leaky
{
   my $closure = sub { $foo++ };
   return $closure;
}

my $x = leaky();
my $y = leaky();
print $y->(), $/ while $x->() < 10;
----
1
3
5
7
9
[download]

The output seemed to be correct ...

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