def check_partial_imagemagick_versions
      prefix = config_string('prefix') || ''
      matches = [
        prefix + '/lib/lib?agick*',
        prefix + '/include/ImageMagick',
        prefix + '/bin/Magick-config'
      ].map do |file_glob|
        Dir.glob(file_glob)
      end
      matches.delete_if(&:empty?)
      return unless !matches.empty? && matches.length < 3

      msg = "\nWarning: Found a partial ImageMagick installation. Your operating system likely has some built-in ImageMagick libraries but not all of ImageMagick. This will most likely cause problems at both compile and runtime.\nFound partial installation at: " + prefix + "\n"
      Logging.message msg
      message msg
    end
def check_partial_imagemagick_versions
      prefix = config_string('prefix') || ''
      matches = [
        prefix + '/lib/lib?agick*',
        prefix + '/include/ImageMagick',
        prefix + '/bin/Magick-config'
      ].map do |file_glob|
        Dir.glob(file_glob)
      end
      matches.delete_if(&:empty?)
      return unless !matches.empty? && matches.length < 3

      msg = "\nWarning: Found a partial ImageMagick installation. Your operating system likely has some built-in ImageMagick libraries but not all of ImageMagick. This will most likely cause problems at both compile and runtime.\nFound partial installation at: " + prefix + "\n"
      Logging.message msg
      message msg
    end
Ubuntu (maybe other systems) comes with a partial installation of
 ImageMagick in the prefix /usr (some libraries, no includes, and no
 binaries). This causes problems when /usr/lib is in the path (e.g., using
 the default Ruby installation).