Mysql – ERROR: Error installing thesql2: ERROR: Failed to build gem native extension

I am having some problems when trying to install gem install mysql2 -v '0.3.17' for Rails. When I try to install it by running gem install mysql2 -v '0.3.17' or gem install mysql2 -v '0.3.17' it gives me the following error:

ERROR:  Error installing mysql2:
    ERROR: Failed to build gem native extension.


Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the file for more
details.  You may need configuration options.

Provided configuration options:
    --with-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
    --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-mysql-config
    --without-mysql-config

Gem files will remain installed in `..../gems/ruby-1.9.3-p392/gems/mysql2-0.3.17 for inspection`.
Results logged to `.../gems/ruby-1.9.3-p392/extensions/x86_64-darwin-14/1.9.1/mysql2-0.3.17/gem_make.out`

How can I fix this and successfully install mysql2?

Thanks all .