Monthly Archives: March 2018

That silly moment when a ruby gem doesn’t install

A few days ago I was helping a user to install a custom Dradis plugin.

As you may already know, Dradis plugins are ruby gems and we manage them with bundler.

The final step in the installation process usually looks something like this:

bundle install --without development,test


bundle update --without development,test [custom_gem]

But at some point in the installation history, a mix of both commands was run, probably something like:

bundle install --without development,test [custom_gem]

This command is wrong, bundle install does not expect a specific gem as a parameter. So the custom_gem parameter is handled by bundler as one of the groups of gems not to be installed. Bundler notifies us about that:

Gems in the groups developement,test and custom_gem were not installed.

We may notice that warning (or not), and try to execute the command correctly:

bundle install --without development,test

But we will see the same warning about custom_gem not being installed. This is because bundler uses a config file to cache some configuration options, like the –without option. That file probably in the same app folder under:


If we check its contents, it looks like:

BUNDLE_WITHOUT: "developement,test:custom_gem"

Until we delete that file or edit it to remove the custom_gem from it, we may have a hard time installing our gem.