To prevent you from inadvertently loading mod_perl 1.0 modules, mod_perl 2.0 Perl modules are installed into dedicated directories under Apache2/. The Apache2 module prepends the locations of the mod_perl 2.0 libraries to @INC: @INC is the same as the core @INC, but with Apache2/ prepended. This module has to be loaded just after mod_perl has been enabled. This can be accomplished with:

use Apache2 ( );

in the startup file. If you don't use a startup file, you can add:

PerlModule Apache2

to httpd.conf, due to the order in which the PerlRequire and PerlModule directives are processed.