gem install mysql reports extconf.rb failed error.

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

        /usr/bin/ruby1.8 extconf.rb --with-mysql-config=/usr/local/mysql/bin/mysql_config
extconf.rb:10: command not found: /usr/local/mysql/bin/mysql_config --cflags
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
Check the mkmf.log file for more
You may need configuration options.

Provided configuration options:
    --without-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=/usr/bin/ruby1.8
    --with-mysql-config

 sudo apt-get install libmysqlclient-dev









 # The package description is: This package includes development libraries and header files.