class Metanorma::Utils::Log

def save_to(filename, dir = nil)
  dir ||= File.dirname(filename)
  new_fn = filename.sub(/\.err\.html$/, ".html")
  b = File.join(dir, File.basename(new_fn, ".*"))
  @filename = "#{b}.err.html"
  @htmlfilename = "#{b}.html"
end