use EV;
use Coro::EV;
use Coro::Handle;
use Devel::Gladiator qw/arena_ref_counts/;

my $c = 0;

while() {

    warn arena_ref_counts()->{SCALAR};

    open my $fh, '/dev/null';

    $fh = unblock $fh;

    Coro::EV::_readable_ev(tied *$fh); #leak 1 SCALAR per iter
    #Coro::Handle::FH::_readable_anyevent(tied *$fh); #not leak

    $fh->close();
    exit if $c++ == 100; #leak 100 scalars and exit
};