I’m working on a Rails 3.2 application and I’m planning to install activeadmin for managing resources. However, when I add gem 'activeadmin' to the Gemfile and run bundle, it produces this error:
NoMethodError: undefined method `spec' for nil:NilClass
An error occured while installing formtastic (2.1.1), and Bundler cannot continue.
Make sure that `gem install formtastic -v '2.1.1'` succeeds before bundling.
Sure enough, when I try to install formtastic only, and add gem formtastic to the Gemfile and run bundle, I get the same error. Is anybody else experiencing this? I’ve tried formtastic versions 2.2.1 and 2.1.1 by the way (because active admin require ~> 2.1.1). Thanks in advance!
This might help you out http://www.tweetegy.com/2011/04/installing-rails-gem-fails-with-undefined-method-spec-for-nilnilclass-error/