docs: def setup_function(self):
          """Runs prior to the global main function."""
          log.options.LogOptions.set_stderr_log_level('google:INFO')
          if app.get_options().debug:
              log.options.LogOptions.set_stderr_log_level('google:DEBUG')
          if not app.get_options().build_root:
              app.set_option('build_root', os.path.join(
                  app.get_options().butcher_basedir, 'build'))
          self.buildroot = app.get_options().build_root
          if not os.path.exists(self.buildroot):
              os.makedirs(self.buildroot)
          if app.get_options().disable_cache_fetch:
              self.options['cache_fetch'] = False
          if app.get_options().disable_hardlinks:
              base.BaseBuilder.linkfiles = False