clockspeed problem under FreeBSD 4.0

I'm trying to get clockspeed-0.62 running under FreeBSD 4.0, but I'm
having a problem.

Yes, I know it's an old OS version, but it will be a while before I can
upgrade ... and all other djb utilities work fine.

The problem is this: whenever I run clockspeed, the program exits at the
"not possible" statement below (from the clockspeed.c source code):

  for (;;) {
    FD_ZERO(&rfds);
    FD_SET(0,&rfds);

    tvselect.tv_sec = 3;
    tvselect.tv_usec = 0;

    if (select(1,&rfds,(fd_set *) 0,(fd_set *) 0,&tvselect) == 1) {
      r = read(0,buf,sizeof buf);
      if (r <= 0) _exit(1); /* not possible */

Have any of you seen this before, and if so, is there a workaround?

Thanks in advance.

-- 
 Lloyd Zusman
 [email protected]