no trace file in perl trace mode

["Vitaly V. Ch" <vi...@gmail.com>]

I try to trace my perl script under mod_perl2 according to

http://perl.apache.org/docs/1.0/guide/debug.html#Non_Interactive_Perl_Debugging_under_mod_perl:

>Non-Interactive Perl Debugging under mod_perl
>
>To debug scripts running under mod_perl either use Apache::DB
(interactive Perl debugging) or an older non-interactive method as
described below.
>
>The NonStop debugger option enables you to get some decent debugging
information when running under mod_perl. For example, before starting
the server:
>
>  % setenv PERL5OPT -d
>  % setenv PERLDB_OPTS "NonStop=1 LineInfo=db.out AutoTrace=1 frame=2"
>
>Now watch db.out for line:filename info. This is most useful for
tracking those core dumps that normally leave us guessing, even with a
stack trace from gdb. db.out will show you what Perl code triggered
the core dump. 'man perldebug' for more PERLDB_OPTS. Note that Perl
will ignore PERL5OPT if PerlTaintCheck is On.


but after apachectl restart no file named db.out was created/detected.

I'm confused