Yeah, got it.
And also added imports for (scheme lazy).
https://github.com/scheme-requests-for-implementation/srfi-216/pull/2

On 04/12/2020 12:02, Wolfgang Corcoran-Mathe wrote:
> On 2020-12-04 11:49 +0800, Vladimir Nikishkin wrote:
>>>> If I can bother you to test the `current=jiffy`-based one once again,
>>>> please?
>>>
>>> This test still fails under CHICKEN, and a similar expression also
>>> fails on chibi:
>>>
>>>     (check (> (- (runtime) (runtime)) 0) => #t)
>>>
>>> The check here is inherently non-portable: only Schemes with slow
>>> evaluation or large values of (jiffies-per-second) will give
>>> different values for the two calls of runtime.  It should probably
>>> be deleted.
>>>
>>
>> Well, if it measures the difference in microseconds, and the execution
>> is faster than a microsecond... yeah, you are right.
>> I think, I will need to add a wait.
>
> On CHICKEN and chibi (jiffies-per-second) gives 1000, so even a slow
> system is likely to give the same value twice.
>
> In the absence of a portable sleep procedure, here's a hack using
> current-second:
>
>     (check
>      (let ((t (runtime))
>            (cur (current-second)))
>        (let lp ()
>          (unless (> (current-second) cur)
>            (lp)))
>        (> (- (runtime) t) 0))
>      => #t)
>
> One other thing which I forgot to include in the last email: you'll
> also need to either import (scheme write) or get rid of `display' in
> `parallel-execute'.
>