Gem::Source#new_dependency_resolver_set

# File tmp/rubies/ruby-4.0.0/lib/rubygems/source.rb, line 220
def new_dependency_resolver_set
  return Gem::Resolver::IndexSet.new self if uri.scheme == "file"

  fetch_uri = if uri.host == "rubygems.org"
    index_uri = uri.dup
    index_uri.host = "index.rubygems.org"
    index_uri
  else
    uri
  end

  bundler_api_uri = enforce_trailing_slash(fetch_uri) + "versions"

  begin
    fetcher = Gem::RemoteFetcher.fetcher
    response = fetcher.fetch_path bundler_api_uri, nil, true
  rescue Gem::RemoteFetcher::FetchError
    Gem::Resolver::IndexSet.new self
  else
    Gem::Resolver::APISet.new response.uri + "./info/"
  end
end