[racket] scheme_call_enable_break

Laurent <laurent.orseau at gmail.com> writes:

> (sync/timeout 0 (scheme_fd_to_semaphore s MZFD_CREATE_READ #t))
>
> Unfortunately this does not work :)
> It always returns #f.

I'm not familiar with `sync/timeout' or `scheme_fd_to_semaphore', but
from `sync/timeout's documentation:

  "A zero value for timeout is equivalent to (lambda () #f). In either
  case, each evt is checked at least once before returning #f or calling
  timeout."

So, I guess it's not a surprise that your call always returns `#f'. It's
not blocking/waiting, how one would want in this situation.