http://search.cpan.org/~gozer/mod_perl-1.29/lib/Apache/Debug.pm

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

for docs

basically you have to start apache in -X mode

you may also find this useful

http://search.cpan.org/~stas/Apache-Test-1.09/lib/Apache/Test.pm

it can start an apache process and then run your tests

http://perl.apache.org/docs/general/testing/testing.html

has all the docs