"gem install mysql" failed. This might be another stupid question, but
really block me for couple of days.

I tried gem:
     gem install mysql -- --with-mysql-config=/usr/bin/mysql_config

and got:
    ERROR:  Error installing mysql:
        ERROR: Failed to build gem native extension.

    /usr/local/bin/ruby extconf.rb
--with-mysql-config=/usr/bin/mysql_config
    extconf.rb:1: command not found: /usr/bin/mysql_config --cflags
    *** extconf.rb failed ***

This might be something wrong with mysql becouse 'mysql_config' can not
be located.
    [root@localhost ~]# whereis mysql_config
    mysql_config:

I also tried mysql-ruby:
    [root@localhost mysql-ruby-2.8.1]# ruby extconf.rb
--with-mysql-dir=/usr/bin/mysql
    checking for mysql_query() in -lmysqlclient... no
    checking for main() in -lm... no
    checking for mysql_query() in -lmysqlclient... no
    checking for main() in -lz... no
    checking for mysql_query() in -lmysqlclient... no
    checking for main() in -lsocket... no
    checking for mysql_query() in -lmysqlclient... no
    checking for main() in -lnsl... no
    checking for mysql_query() in -lmysqlclient... no
    checking for main() in -lmygcc... no
    checking for mysql_query() in -lmysqlclient... no
    *** extconf.rb failed ***


here is the env info:
    Linux version 2.6.18-128.4.1.el5PAE (mockbuild@builder16.centos.org)
(gcc version 4.1.2 20080704 (Red Hat 4.1.2-44)) #1 SMP Tue Aug 4
20:58:34 EDT 2009

    [root@localhost ~]# whereis mysql
    mysql: /usr/bin/mysql /usr/local/lib/mysql /usr/share/mysql
/usr/share/man/man1/mysql.1.gz
   [root@localhost ~]# ruby -v
   ruby 1.8.6 (2008-03-03 patchlevel 114) [i686-linux]
   [root@localhost ~]# rails -v
   Rails 2.3.3
   [root@localhost ~]# gem -v
   1.3.5

any suggestion will be appreciate :)

Jason Wei wrote:
> This might be something wrong with mysql becouse 'mysql_config' can not
> be located.
>     [root@localhost ~]# whereis mysql_config
>     mysql_config:

Indeed, you are missing the MySQL client and (probably) development
files. You should install them using your package manager and try again.

--
Roderick van Domburg
http://en.railscluster.nl

Roderick van Domburg wrote:
> Jason Wei wrote:
>> This might be something wrong with mysql becouse 'mysql_config' can not
>> be located.
>>     [root@localhost ~]# whereis mysql_config
>>     mysql_config:
>
> Indeed, you are missing the MySQL client and (probably) development
> files. You should install them using your package manager and try again.
>
> --
> Roderick van Domburg
> http://en.railscluster.nl

thx Roderick.
could u give me hint. what exactly package I should install.

    [root@localhost ~]# rpm -qa|grep -i mysql
    MySQL-client-5.1.37-0.glibc23
    MySQL-server-5.1.37-0.glibc23

Jason Wei wrote:
> Roderick van Domburg wrote:
>> Jason Wei wrote:
>>> This might be something wrong with mysql becouse 'mysql_config' can not
>>> be located.
>>>     [root@localhost ~]# whereis mysql_config
>>>     mysql_config:
>>
>> Indeed, you are missing the MySQL client and (probably) development
>> files. You should install them using your package manager and try again.
>>
>> --
>> Roderick van Domburg
>> http://en.railscluster.nl
>
> thx Roderick.
> could u give me hint. what exactly package I should install.
>
>     [root@localhost ~]# rpm -qa|grep -i mysql
>     MySQL-client-5.1.37-0.glibc23
>     MySQL-server-5.1.37-0.glibc23

I reinstall the related rpm.

these are needed.

perl-DBD-MySQL-3.0007-2.el5
mysql-5.0.45-7.el5
mysql-server-5.0.45-7.el5
mysql-devel-5.0.45-7.el5