here is what i found on http://wiki.bestpractical.com/view/Troubleshooting
Can't locate Apache/Response.pm in @INC ...
Can't load Perl file: bin/webmux.pl for server localhost:0, exiting...
Found this issue in Aurora SPARC Linux 2.0 (Fedora Core 3 for SPARC)
when trying to install...
turns out that after installing all the modules for rt,
I still had an ancient verion of CGI.pm,
which was not intended to correctly detect the mod_perl2 modules vs.
regular mod_perl. Upgrading CGI via CPAN quickly resolved this problem after an
embarrassing number of hours troubleshooting.
If Apache refuses to start after you add PerlRequire bin/webmux.pl to your
config and you're sure you've got a valid mod_perl2 installation,
try upgrading CGI to the latest version.
maybe you can try first to update your CGI.pm module.
Did you find your call to webmux.pl in your apache conf ?
old previous useless response :
well, can you post the code from the script that tries to launch webmux.pl ?
but i would suggest a simple solution, if you don't have administrative rights or don't want
to go further in your perl conf :
add at top of your code (but below use strict...never forget this one)
in your script the code :
use lib "/usr/sbin/"
so you script will be able to use libraries located in /usr/sbin/