Having problems installing mod_perl on Slackware

[Eric Snyder <suppressed>]

Be patient with me, I am new to perl. I am attempting to install perl, 
apache and mod_perl so I can use the mod_perl cgi in BackupPC. I get 
through most of the process but my mod_perl MAKE blows up. I am 
following the instructions at 
http://perl.apache.org/docs/2.0/user/install/install.html

Running as root I have:

Installed Bundle::Apache2 from CPAN - no problems.

configured perl with:
./Configure -des -Uusethreads
% make && make test && make install

all no problems

I then downloaded and extracted apache 2.2.4
I then changed directories to mod_perl-2.0.3 and ran:

perl Makefile.PL MP_USE_STATIC=1 MP_AP_PREFIX=/usr/src/httpd-2.2.4 
MP_AP_CONFIGURE="--with-mpm=prefork"

This seemed to go with no problems.

Make totally blew up on me. I get massive errors from the start. Here is 
the top of the output:

make[1]: Entering directory `/usr/src/mod_perl-2.0.3/src/modules/perl'
cc -I/usr/src/mod_perl-2.0.3/src/modules/perl 
-I/usr/src/mod_perl-2.0.3/xs -I/usr/src/httpd-2.2.4/include 
-I/usr/src/httpd-2.2.4/srclib/apr/include 
-I/usr/src/httpd-2.2.4/srclib/apr-util/include 
-I/usr/src/httpd-2.2.4/os/unix -fno-strict-aliasing -pipe 
-Wdeclaration-after-statement -I/usr/local/include 
-I/usr/local/lib/perl5/5.8.8/i686-linux/CORE -DMOD_PERL -DMP_COMPAT_1X 
-O2 -c mod_perl.c
In file included from /usr/src/httpd-2.2.4/include/httpd.h:43,
                from modperl_apache_includes.h:27,
                from mod_perl.h:20,
                from mod_perl.c:17:
/usr/src/httpd-2.2.4/include/ap_config.h:25:17: apr.h: No such file or 
directory
In file included from /usr/src/httpd-2.2.4/include/ap_config.h:26,
                from /usr/src/httpd-2.2.4/include/httpd.h:43,
                from modperl_apache_includes.h:27,
                from mod_perl.h:20,
                from mod_perl.c:17:
/usr/src/httpd-2.2.4/srclib/apr-util/include/apr_hooks.h:20:17: apu.h: 
No such file or directory
In file included from 
/usr/src/httpd-2.2.4/srclib/apr-util/include/apr_hooks.h:22,
                from /usr/src/httpd-2.2.4/include/ap_config.h:26,
                from /usr/src/httpd-2.2.4/include/httpd.h:43,
                from modperl_apache_includes.h:27,
                from mod_perl.h:20,
                from mod_perl.c:17:
/usr/src/httpd-2.2.4/srclib/apr/include/apr_tables.h:25:17: apr.h: No 
such file or directory
In file included from 
/usr/src/httpd-2.2.4/srclib/apr/include/apr_pools.h:38,
                from 
/usr/src/httpd-2.2.4/srclib/apr/include/apr_tables.h:26,
                from 
/usr/src/httpd-2.2.4/srclib/apr-util/include/apr_hooks.h:22,
                from /usr/src/httpd-2.2.4/include/ap_config.h:26,
                from /usr/src/httpd-2.2.4/include/httpd.h:43,
                from modperl_apache_includes.h:27,
                from mod_perl.h:20,
                from mod_perl.c:17:
/usr/src/httpd-2.2.4/srclib/apr/include/apr_errno.h:52: error: syntax 
error before "apr_strerror"
/usr/src/httpd-2.2.4/srclib/apr/include/apr_errno.h:53: error: syntax 
error before "apr_size_t"
/usr/src/httpd-2.2.4/srclib/apr/include/apr_errno.h:53: warning: data 
definition has no type or storage class



What is wrong and how do I fix this?