    # File ext/RMagick/extconf.rb, line 53
    def check_multiple_imagemagick_versions()
       versions = []
       path = ENV['PATH'].split(File::PATH_SEPARATOR)
       path.each do |dir|
          file = File.join(dir, "Magick-config")
          if File.executable? file
             vers = `#{file} --version`.chomp.strip
             prefix = `#{file} --prefix`.chomp.strip
             versions << [vers, prefix, dir]
          end
       end
       versions.uniq!
       if versions.size > 1
          msg = "\nWarning: Found more than one ImageMagick installation. This could cause problems at runtime.\n"
          versions.each do |vers, prefix, dir|
             msg << "         #{dir}/Magick-config reports version #{vers} is installed in #{prefix}\n"
          end
          msg << "Using #{versions[0][0]} from #{versions[0][1]}.\n\n"
          Logging::message msg
          message msg
       end
    end