Install a specific version of a gem

Sometimes you want one distinct version of RubyGems to be installed to replicate the same behavior across multiple servers.

Usually would do this to update your RubyGems, but this always takes you to the latest version:

gem update --system

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When a gem author releases a new version to Rubygems, usually a tag with the version number (e.g. v1.2.0) is created an pushed to Github, so everyone can check out or take a look at the source code at this point version release at a later time.
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Whenever Firefox updates, all your Cucumber features that use Selenium break. This is annoying.

In order to remedy this, version 0.5.0 of our geordi gem comes with a script that helps you create an unchanging ...

Sometimes I ran across a GitHub merge request of a gem where it was not completely obvious in which version the change was released. This might be the case for a bugfix PR that you want to add to your project.

Git can help you to find the next gi...

Plugins (and gems) are typically tested using a complete sample rails application that lives in the spec folder of the plugin. If your gem is supposed to work with multiple versions of Rails, you might want to use to separate apps - one for each...

As described by the linked Stackoverflow answer, run these commands:

sudo add-apt-repository ppa:git-core/ppa -y
sudo apt-get update
sudo apt-get install git
git --version

This will get you Git 2.6.4 (as of Dec 2015).

Troubleshooting...

Updated the card with our current best practice (shared app code and specs via symlinks).

When installing a gem you can use version comparators like >= or ~>. That way it is possible to fetch the latest version of Bundler 1 with this command:

gem install bundler -v '~>1'

[How to install bundler for Ruby < 2.3](/makandra/...

You can specify the version of bundler to execute a command (most often you need an older version of bundler, but don't want to uninstall newer ones):

bundle _1.0.10_ -v
Bundler version 1.0.10

An example is rails 3.2, which fre...

paper_trail is an excellent gem to track record versions and changes.

You almost never want to reimplement something like it yourself. If you need to log some extra information, you can add them on top.

It comes with a really good README file...