The configure section of the PHP4 rpm specfile has --with-mysql turned on.
The mysql extension for PHP4 is also built later in the specfile. This
causes problems after compilation because the mysql extensions are trying
to load a second time when you turn on the extension in the php.ini config
All I needed to do to fix this in the specfile was take out the
--with-mysql flag in the configuration section.
Also, unless RedHat is planning to redistribute MySQL as their own package
with lowercase letters, it would be nice if they changed the require
directive to require MySQL instead of mysql. The MySQL rpms that are on
MySQL mirrors install properly as MySQL.
This is already fixed in our build tree.