Interesting problem and I think you just helped finding the bug I was trying to catch for the past 3 days.....
I think putting an eval block within the child code and the exit-ing instead of die-ing will solve the problem.
At least in the example you gave: 
#!/usr/bin/perl -w

use strict;

my $num = '123'; # an external database ID, for example
warn "(PID $$) Beginning transaction #$num ";
eval {
    my $pid = fork();
    if ($pid) {
        warn "\t(PID $$) the parent does OK";
    }
    else {
        eval {
            warn "\t(PID $$) the child fails";
            die "\t(PID $$) Child process failure";
        };
        warn $@ if $@;
        exit;
    }
};
if ($@) {
    warn "(PID $$) Rolling back transaction #$num: died in eval with $
+@";
}
else {
    warn "(PID $$) Committing transaction #$num";
}

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In reply to Re: forked die() in eval block has counterintuitive behavior? by szabgab
in thread forked die() in eval block has counterintuitive behavior? by rlucas

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