MySQL2 gem won't install

Question

I have been trying to install Gitlab on my Ubuntu 12.04 server for a long time, and all goes well until I run bundle install.

It says it is unable to instal

Answer 1

It does tell you a generic possible problem:

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.

That's your clue.

Make sure you've installed the MySQL client repo, along with the associated "devel" package. Languages like Ruby, Python, Perl, etc., need the libraries and headers installed so they can compile native modules providing the interface from the language to the drivers.

Also, you'll need mysql_config, which is installed by:

sudo apt-get install libmysqlclient-dev

I was able to duplicate your problem with my Ubuntu VM, and fix it after installing libmysqlclient-dev.

It places mysql_config in /usr/bin/mysql_config, and both gem install mysql and gem install mysql2 were able to install successfully.