scm_puts ("This object should be a markup: ", scm_current_error_port ());
scm_display (markup, scm_current_error_port ());
scm_puts ("\n", scm_current_error_port ());
scm_puts ("This object should be a markup: ", scm_current_error_port ());
scm_display (markup, scm_current_error_port ());
scm_puts ("\n", scm_current_error_port ());