Gem::SpecFetcher#search_for_dependency

# File tmp/rubies/ruby-4.0.0/lib/rubygems/spec_fetcher.rb, line 86
def search_for_dependency(dependency, matching_platform = true)
  found = {}

  rejected_specs = {}

  list, errors = available_specs(dependency.identity)

  list.each do |source, specs|
    if dependency.name.is_a?(String) && specs.respond_to?(:bsearch)
      start_index = (0...specs.length).bsearch {|i| specs[i].name >= dependency.name }
      end_index   = (0...specs.length).bsearch {|i| specs[i].name > dependency.name }
      specs = specs[start_index...end_index] if start_index && end_index
    end

    found[source] = specs.select do |tup|
      if dependency.match?(tup)
        if matching_platform && !Gem::Platform.match_gem?(tup.platform, tup.name)
          pm = (
            rejected_specs[dependency] ||= \
              Gem::PlatformMismatch.new(tup.name, tup.version))
          pm.add_platform tup.platform
          false
        else
          true
        end
      end
    end
  end

  errors += rejected_specs.values

  tuples = []

  found.each do |source, specs|
    specs.each do |s|
      tuples << [s, source]
    end
  end

  tuples = tuples.sort_by {|x| x[0].version }

  [tuples, errors]
end