Installing mysql2 gem for Ruby on Rails with Mac OSX 10.6

Question

I am having a problem installing the mysql2 gem.

This comes up when I do gem install mysql2:

Marks-MacBook-Pro:~ Mark$ gem install mysql2 Building native extensions.  This could take a while... ERROR:  Error installing mysql2: ERROR: Failed to build gem native extension.  /Users/useruser/.rvm/rubies/ruby-1.9.2-p136/bin/ruby extconf.rb checking for rb_thread_blocking_region()... yes checking for mysql_query() in -lmysqlclient... no checking for main() in -lm... yes checking for mysql_query() in -lmysqlclient... no checking for main() in -lz... yes 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 *** 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=/Users/useruser/.rvm/rubies/ruby-1.9.2-p136/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     --with-mlib     --without-mlib     --with-mysqlclientlib     --without-mysqlclientlib     --with-zlib     --without-zlib     --with-mysqlclientlib     --without-mysqlclientlib     --with-socketlib     --without-socketlib     --with-mysqlclientlib     --without-mysqlclientlib     --with-nsllib     --without-nsllib     --with-mysqlclientlib     --without-mysqlclientlib     --with-mygcclib     --without-mygcclib     --with-mysqlclientlib     --without-mysqlclientlib   Gem files will remain installed in /Users/useruser/.rvm/gems/ruby-1.9.2-p136/gems/mysql2-0.2.6 for inspection. Results logged to /Users/useruser/.rvm/gems/ruby-1.9.2-p136/gems/mysql2-0.2.6/ext/mysql2/gem_make.out 

Also when I use rails server this comes up:

Could not find gem 'mysql2 (>= 0, runtime)' in any of the gem sources listed in your Gemfile. 

Answer 1

It seems that it cannot find the MySQL library. Have you installed MySQL?
Try installing it via homebrew:

brew install mysql 

or install it via macports or fink or whatever you prefer.

Then try again with:

gem install mysql2