Invalid "recursive invocation" with Coro::Handle + eval

[Harry Mason]

This code seems to trigger an internal error somewhere in either
Coro, Coro::EV, or libev. Am I doing something wrong, or is there a bug?

I appreciate you can't use the same Coro::Handle instance simultaneously
from two coroutines, but here only one coroutine is using it.
 
This is a simplified test case. The use of throw() is desired for other
reasons; I know there are other possible approaches in this example.

If nothing is entered on stdin, we expect $line1 to be
"interrupted reading first line: interrupt\n"
but also $line2 ends up as
"interrupted reading next line: recursive invocation of readable_ev or
writable_ev (concurrent Coro::Handle calls on same handle?), detected
at /usr/lib/perl5/Coro/Handle.pm line 551.\n"

I am also seeing my program's main EV::loop croak with the message
"Coro::State object required". It seems to have a similar cause but it
is hard to pin down.

Cheers
Harry

--- 8< ---

#!/usr/bin/perl
use 5.14.0;
use warnings;

use Coro;
use EV;
use AnyEvent;
use Coro::AnyEvent;
use Coro::Handle;

my $line1;
my $line2;
my $worker = async {
    my $fh = unblock \*STDIN;

    eval {
        $line1 = $fh->readline;
    };
    if ($@) {
        $line1 = "interrupted reading first line: $@";
    }

    eval {
        $line2 = $fh->readline;
    };
    if ($@) {
        $line2 = "interrupted reading next line: $@";
    }
};

Coro::AnyEvent::sleep(1);
$worker->throw("interrupt\n");
$worker->ready;
$worker->join;

print $line1, $line2;