Fixing bundle install/update of do_mysql on Mac OS X

bash.log

FXS-iMac-3:newsletter tomas$ sudo bundle update
 
Fetching gem metadata from http://rubygems.org/.........
.....
Installing do_mysql (0.10.8) with native extensions 
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby 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=/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby
	--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 /Library/Ruby/Gems/1.8/gems/do_mysql-0.10.8 for inspection.
Results logged to /Library/Ruby/Gems/1.8/gems/do_mysql-0.10.8/ext/do_mysql/gem_make.out
An error occured while installing do_mysql (0.10.8), and Bundler cannot continue.
Make sure that `gem install do_mysql -v '0.10.8'` succeeds before bundling.

FXS-iMac-3:newsletter tomas$ bundle config build.do_mysql --with-mysql-dir=/usr/local/mysql/
FXS-iMac-3:newsletter tomas$ sudo bundle update
.....
Your bundle is updated! Use `bundle show [gemname]` to see where a bundled gem is installed.