Hi,

I just checked on my RHEL boxes, and even your method to compile the
module works fine there. What version of MySQL are you using and from
which source did you take it? Official MySQL rpm files from mysql.com?
Self-compiled? 

The first strange thing in my eyes is, that mysql_config is not there.
Every rpm I know of installs it in /usr/bin as part of the basic MySQL
package. ANd the second strange thing is the error while running your
test code.

> [richard@www mysql-ruby-2.7]$ ruby ./test.rb localhost root ertgnhbr
> ./test.rb:143: undefined method `client_version' for Mysql:Class  
> (NoMethodError)

I don't think that the compiler is the source of your problems. Can you
supply the MySQL version and from where you have taken it? Or where it
is installed? 

Regards,
Oliver

-- 
Oliver Andrich --- oliver.andrich / gmail.com --- http://roughbook.de/