Mysql problem after upgrade to 5.0

I’m posting this as an FYI – for other people who might encounter the
same problem – I couldn’t find any clear instructions on how to resolve

I upgraded from mysql 4.1 to 5.0, at which point 2 different errors

error while trying to create table customers; Could not load driver
( cannot open shared object file: No such file or
directory - /usr/lib64/site_ruby/1.8/x86_64-linux/

Errno::ENOENT in SearchController#search

No such file or directory - /tmp/mysql.sock

the solution was to install the latest ruby code – in my case (fedora)

yum upgrade ruby*

did the trick.