无法安装 do_mysql gem?

I'm trying to install the do_mysql on my Snow Leopord system Macbook Pro 13", but I keep getting this error:

n216-160:~ myself$ sudo gem1.9 install do_mysql
Password:
Building native extensions.  This could take a while...
ERROR:  Error installing do_mysql:
    ERROR: Failed to build gem native extension.

/opt/local/bin/ruby1.9 extconf.rb
checking for mysql_query() in -lmysqlclient... no
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
    --without-make-prog
    --srcdir=.
    --curdir
    --ruby=/opt/local/bin/ruby1.9
    --with-mysql-config
    --without-mysql-config
    --with-mysql-dir
    --without-mysql-dir
    --with-mysql-include
    --without-mysql-include=${mysql-dir}/include
    --with-mysql-lib
    --without-mysql-lib=${mysql-dir}/lib
    --with-mysqlclientlib
    --without-mysqlclientlib


Gem files will remain installed in /opt/local/lib/ruby1.9/gems/1.9.1/gems/do_mysql-0.10.0 for inspection.
Results logged to /opt/local/lib/ruby1.9/gems/1.9.1/gems/do_mysql-0.10.0/ext/do_mysql_ext/gem_make.out
n216-160:~ myself$ 

我不知道为什么.我还按照其他人的建议，用 MySQL 5.4.3 beta，64 位重新安装了我的 MySQL 版本，但没有骰子.有谁知道出了什么问题?

sudo apt-get install libmysqlclient-dev