> Look at the code of CGI::Carp - it's implemented there. They check if the exception was thrown from an eval by examining $^S.

Either I didn't make my self clear or you misunderstood or I misunderstand your comment. :) The issue is that the eval's are in modules not under my control; specifically, they're from CPAN if it matters. Those modules are essentially getting in my way and triggering my __DIE__ signal handler when I don't want that. They don't die, but they do trigger my handler uneccesarily.

$SIG{__DIE__} = sub {
   return if $^S;

   ...

   print(STDERR $_[0]);
   exit($! || ($? >> 8) || 255);
};
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I did something similar on one of my first tries to find out what was going on and to fix this. I looked at the call stack and if there wasn't a ".cgi" file in the list then assumed I was in the "compile" stage and just returned. Not as elegent as using $^S but it worked. If I had to do something like this, I like the $^S way better now that I know about it.

In the end, I'd really like to know why I had to do anything like this. If we have code like:

package X;

BEGIN { whatever; }

$main::SIG{__DIE__} = \&some_function; # when does this get run?

sub new { ... }
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In what phase is that SIG handler assigned? I would have thought it was in an implied INIT, but the code acts like it's in an implied BEGIN. I ended up solving the entire issue by putting that line in an explicit INIT block, but why did I have to do that?