rails `require’: cannot load such file — mysql2/mysql2 (LoadError)


You want to use a different ruby version from the one you have initially installed and build your application with, but when you change it in your rvm installation you get the following error:


To make it work again you will have to uninstall the mysql2 gem and install it again in the new ruby version with the option –platform=ruby.

RVM and RubyGems versions


You would like to upgrade your rubygems version from 1.8.17 to the latest version 2.0.7 for example.


You can upgrade to a specific or the latest gem version and relate that to a specific rvm ruby that you have installed.
So if for example you have ruby-1.9.3-p327 and ruby-2.0.0-p247, you can have different gem version (or the same if you want) for each ruby version.

To upgrade to the latest one in the ruby-2.0.0-p247 for example you could do the following:

Get github to link your commits to your user account if you have more than one git accounts


You would like to link the commits to a github repository to your github account but you may have different git accounts (ie gitolite etc).
So you would need to specify in the config file which account you want to use.


There is a help page in github that describes this problem here, but they recommend to change your global settings which is maybe not what you want.
So you could the following to change only the current project settings:

And to check the settings:

Stop github asking your username

You are working with a git repository but after first cloning the project to your localhost and trying to push changes afterwards, github is asking for you username and password.

Edit your git configuration and make sure that it uses the git protocol instead of https, so in your ~/project/.git/config file