I cannot figure out how to make bundler to install platform-dependent gems.
As recommended in bundler docs I use :platforms option in the Gemfile:
# Gemfile
gem "pry-byebug", platforms: [:mri_20, :mri_21]
gem "pry-debugger", platforms: :mri_19
And I don't include the dependencies to my_gem.gemspec, 'cause it doesn't provide tools for platform-dependent specification.
When I run bundle all is OK: the corresponding gem is included to the Gemfile.lock as expected.
The problem arises when I use my gem in another ("host") gem.
When I run bundle in the host gem root, the platform-specific dependencies are skipped and missing in the host_gem/Gemfile.lock.
It seems like Bundler installs only dependencies specified in the gemspec, not in the Gemfile.
So my question is how to properly define platform-specific dependencies to be loaded by depending gems?
