Rails – gem install thesql doesn’t work on cygwin

You just add the following line to your local ~/.gemrc file (it is in your home folder):

gem: --no-document

or you can add this line to the global gemrc config file.

Here is how to find it (in Linux):

strace gem source 2>&1 | grep gemrc

The --no-document option is documented in the RubyGems CLI Reference.

On Debian (or Ubuntu) systems, just install libmysqlclient-dev package using:

sudo apt-get install libmysqlclient-dev

and then:

gem install mysql

It will be installed without any error.