mysql gem and mysql NOT from RPM

Have you ever seen this:

>> require 'mysql'
LoadError: libmysqlclient.so.15: cannot open shared object file: No such file or directory - /usr/local/lib/ruby/gems/1.8/gems/mysql-2.7/lib/mysql.so
from /usr/local/lib/ruby/gems/1.8/gems/mysql-2.7/lib/mysql.so
from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:32:in `require'
from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:509:in `require'
from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:354:in `new_constants_in'
from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:509:in `require'
from (irb):2

I found this happens when your environment for mysql is not setup correctly. The fix is easy. All you need is to add a file in the /etc/profile.d directory called mysql.sh with the correct exports and re-login...

[root@heimdull log]# cat /etc/profile.d/mysql.sh
export LD_LIBRARY_PATH=/usr/local/mysql/lib:$LD_LIBRARY_PATH
export PATH=/usr/local/mysql/bin:${PATH}

That fixes the binary and library paths... MAKE SURE THERE ARE NO MYSQL RPMS INSTALLED...

rpm -qa | grep mysql should give no mysql-[version] or mysql-server-[version] or mysql-devel-[version]

log-in and out...

install the gem

[root@heimdull ~]# gem install mysql -- --with-mysql-config=`which mysql_config`
Building native extensions. This could take a while...
Successfully installed mysql-2.7
1 gem installed

test the new gem:

[root@heimdull current]# RAILS_ENV=production ruby script/console
Loading production environment (Rails 2.1.0)
>> require 'mysql.so'
=> []
>> puts Mysql::VERSION
20700
=> nil
>> exit