# File lib/bundler/gem_version_promoter.rb, line 68
    def sort_versions(dep, spec_groups)
      before_result = "before sort_versions: #{debug_format_result(dep, spec_groups).inspect}" if DEBUG

      @sort_versions[dep] ||= begin
        gem_name = dep.name

        # An Array per version returned, different entries for different platforms.
        # We only need the version here so it's ok to hard code this to the first instance.
        locked_spec = locked_specs[gem_name].first

        if strict
          filter_dep_specs(spec_groups, locked_spec)
        else
          sort_dep_specs(spec_groups, locked_spec)
        end.tap do |specs|
          if DEBUG
            STDERR.puts before_result
            STDERR.puts " after sort_versions: #{debug_format_result(dep, specs).inspect}"
          end
        end
      end
    end