Building native extensions.  This could take a while...
ERROR:  Error installing do_mysql:
        ERROR: Failed to build gem native extension.

/usr/bin/ruby1.8 extconf.rb install do_mysql
extconf.rb:15:in `gets': No such file or directory - install (Errno::ENOENT)
        from extconf.rb:15
Cannot find mysql_config in your path. Please enter a location: