I realise this is a tough one but I'm hoping someone might be to give me new ideas on how to track this error down. Background: a very large application written in Perl and happily running on 5.8 on another server. Moved to new server with 5.10.0 AND changed some code to use Try::Tiny and now we get a lot of these panics.

I've tried reproducing the problem in a small example but have failed. That example looks something like this:

use Try::Tiny;
use Log::Log4perl qw(get_logger :levels);
Log::Log4perl->init_and_watch('/etc/log4.conf', 60);
my $log = get_logger('Q::S');

fred();

sub fred
{
    my $x = try {
        dave();
        0;
    } catch {
        my $ev = $_;
        if (0) {
            eval {
                my $a = 1;
                1;
            } or $log->warn("failed $@");
        } else {
            $log->logwarn("test $_");
        }
        1;
   };
   print "$x\n";
   return if $x;  # <---- this would be q.pl line 1895
}

sub dave
{
   # the following line would be DB.pm line 1380
   my ($sth, $options, @args) = @_;
}
[download]

The big problem is we seem to have to run this code a while before it starts happening and then it happens all the time. I can run the code in debug and I get slightly more out of it:

perl -t -I /home/martin/modules/BET/lib q.pl -n1 -p 9999 -r -c /etc/se
+rvices.ini
Attempt to free unreferenced scalar: SV 0xa7b9650, Perl interpreter: 0
+x9ad0008 at q.pl line 1895, <GEN41> line 1.
Failed to insert into job_audit, panic: attempt to copy freed scalar a
+7b9650 to ad20598 at /home/martin/modules/X/lib/X/DB.pm line 1380, <G
+EN42> line 1.
[download]

Any ideas how to identify the freed scalar and track this down?