Re: Reproducible Research Hackathon: Friday, July 3rd

[bonfacemunyoki@gmail.com (Bonface M. K.)]

Konrad Hinsen <konrad.hinsen@fastmail.net> writes:

> Hi Ludo,
>
>> Apologies for the delay.  What was this bug exactly?
>>
>> I know Bonface addressed an issue related to how the Python 2.4 build
>> system would capture the kernel version via ‘uname’ a build time:
>>
>>   https://gitlab.inria.fr/guix-hpc/guix-past/-/commit/d1977f5dccd73341f363cfa8d58ae3f2b2700ad7
>>
>> But presumably you’re referring to something else, right?
>
> Indeed. The details are here:
>
>   https://gitlab.inria.fr/guix-hpc/guix-past/-/issues/1
>
> Since I won't be able to look into this before my summer vacations,
> I opened an issue as a reminder.
>
> Cheers,
>   Konrad
>
That's strange. To get the right results, you'd have to do a `2L ** 64`.
When I tried `2 ** 63` I got `-9223372036854775808`. There's also an
overflow error. Here's a snippet of what fails from
Python-2.4.6/Lib/test:

```
    # If this fails, probably using a strict IEEE-754 conforming libm, and x
    # is +Inf afterwards.  But Python wants overflows detected by default.
    try:
        x = math.exp(1000000000)
    except OverflowError:
        pass
    else:
        raise TestFailed("overflowing exp() didn't trigger OverflowError")
```

Maybe there's an overflow somewhere and we'd have to tweak libm? I'm
speculating though. I'd have to investigate this later.

-- 
Bonface M. K. (https://www.bonfacemunyoki.com)
One Divine Emacs To Rule Them All
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