The 2.0.4 ebuild is not installing the file apache2-mod_perl-startup.pl. It is located in the ebuild files directory (www-apache/mod_perl/files/2.0.3), but the ebuild is using a directory based off of the ebuild name. Renaming the directory 2.0.4 solved the install problem. This bug was referenced in this closed bug: http://bugs.gentoo.org/show_bug.cgi?id=220909. Reproducible: Always
fixed, thanks