When you're developing a gem, never list the same dependency as both runtime and development dependency in your .gemspec.
So don't do this:
spec.add_dependency 'activesupport'
spec.add_development_dependency 'activesupport', '~> 2.3'
If you do this, your gemspec will not validate and modern versions of Bundler will silently ignore it. This leads to errors like:
Could not find your-gem-0.1.2 in any of the sources
What to do instead
If you want to freeze a different version of a dependency for your tests, prefer putting it into the Gemfile in your gem project directory.
In the example above, have a .gemspec like this:
spec.add_dependency 'activesupport'
Then, in your Gemfile, add the dependency for tests:
gem 'activesupport', '~> 2.3'
gemspec
Posted by Henning Koch to makandra dev (2015-11-02 10:18)