Gem::SpecFetcher#spec_for_dependency

# File tmp/rubies/ruby-3.3.0/lib/rubygems/spec_fetcher.rb, line 153
def spec_for_dependency(dependency, matching_platform=true)
  tuples, errors = search_for_dependency(dependency, matching_platform)

  specs = []
  tuples.each do |tup, source|
    spec = source.fetch_spec(tup)
  rescue Gem::RemoteFetcher::FetchError => e
    errors << Gem::SourceFetchProblem.new(source, e)
  else
    specs << [spec, source]
  end

  [specs, errors]
end