It seems like a strange feature that rubygems wants to know what my development dependencies are, so far I never saw it used to actually load these when running the gem tests.
3 Answers
The documented answer to this question at RubyGems is as follows:
Development dependencies are useful for when someone wants to make modifications to your gem. When you specify development dependencies, another developer can run gem install --dev your_gem and RubyGems will grab both sets of dependencies (runtime and development). Typical development dependencies include test frameworks and build systems.
For example, I may specify spec.add_development_dependency 'minitest'
Adding the --dev flag to the gem install command would then pull in the minitest gem automatically. This feature saves another developer from manually having to identify and install the gems necessary for development.
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