add: errno = 0;
context: skip_via_lseek (char const *filename, int fdesc, off_t offset, int whence){  struct mtget s1;  struct mtget s2;  off_t new_position;  int got_original_tape_position;  got_original_tape_position = (ioctl (fdesc, MTIOCGET, &s1) == 0);  /* known bad device type */  /* && s.mt_type == MT_ISSCSI2 */  new_position = lseek (fdesc, offset, whence);  if (0 <= new_position      && got_original_tape_position      && ioctl (fdesc, MTIOCGET, &s2) == 0      && MT_SAME_POSITION (s1, s2))    {      error (0, 0, _("warning: working around lseek kernel bug for file (%s)\n\  of mt_type=0x%0lx -- see <sys/mtio.h> for the list of types"),	     filename, s2.mt_type);      new_position = -1;    }  return new_position;}