When you install mod_perl-1.99.09, it required CGI-3.00. The problem is that it is installed as /usr/lib/perl5/vendor_perl/5.8.1/CGI.pm which I believe gets overshadowed by the original CGI.pm in /usr/lib/perl5/5.8.1/CGI.pm. This then leads to error in the Apache log close to "Cannot find module Apache.pm....." when you try to run a regular CGI script under mod_perl using ModPerl::Registry or ModPerl::PerlRun because its using the old CGI.pm which isn't fully compatible with mod_perl2.
Additional info: The box that I'm having this trouble on is ACCEPT_KEYWORDS="x86". It is running Apache 2.0.47 and Perl 5.8.0-r12. I installed mod_perl-1.99.09 on this box to go along with Apache 2. I get this in my /var/log/apache2/error_log: [Tue Oct 21 15:10:42 2003] [error] 18133: ModPerl::Registry: Can't locate Apache.pm in @INC (@INC contains: /home/httpd/perl /usr/lib/perl5/vendor_perl/5.8.0/i686-linux/Apache2 /usr/lib/perl5/5.8.0/i686-linux /usr/lib/perl5/5.8.0 /usr/lib/perl5/site_perl/5.8.0/i686-linux /usr/lib/perl5/site_perl/5.8.0 /usr/lib/perl5/site_perl /usr/lib/perl5/vendor_perl/5.8.0/i686-linux /usr/lib/perl5/vendor_perl/5.8.0 /usr/lib/perl5/vendor_perl . /etc/apache2/ /etc/apache2/lib/perl) at /usr/lib/perl5/5.8.0/CGI.pm line 161. On my personal box that's running ~x86, I have Apache 2.0.47-r1, Perl 5.8.1-r2, and mod_perl-1.99.10. I don't have this problem at all. The Apache configs are almost identical except that in 2.0.47-r1 the docroot is changed to /var/www/localhost from /home/httpd in 2.0.47 and below.
Even more additional info: If I rename /usr/lib/perl5/5.8.0/CGI.pm to CGI.pm.bak, mod_perl uses CGI-3.00 and the problem disappears.
I'm confused between the 5.8.1s and the 5.8.0s. What I can tell you is this: vendor_perl overrides things in the perl core. This is done on purpose in the perl ebuild, and has been that way since 5.8.0-r12. So the original description you are worried about should not be happening. If, however, CGI is going into the 5.8.1 directories, but running against 5.8.0, of course it won't be found. I don't see how this could happen in a normal situation, however. Does this give you anything more to go on?
Sorry for the confusion. I had been comparing my x86 and ~x86 boxes. The one I was having the trouble on was 5.8.0 and the directories should have been also. I don't seem to have this problem with perl-5.8.1. Although, I think its because perl-5.8.1's copy of CGI.pm is identical to the one in CGI-3.00.
I think the 5.8.0 box may have had a libperl without the @INC directories moved around. Upgrading libperl should solve it.
