Gem::SpecFetcher#detect

# File tmp/rubies/ruby-3.0.5/lib/rubygems/spec_fetcher.rb, line 132
def detect(type=:complete)
  tuples = []

  list, _ = available_specs(type)
  list.each do |source, specs|
    specs.each do |tup|
      if yield(tup)
        tuples << [tup, source]
      end
    end
  end

  tuples
end