Problems with the giac package : different failures on buildd and porterbox !?

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

Problems with the giac package : different failures on buildd and porterbox !?

Julien PUYDT-2
Hi,

I uploaded a new giac to unstable ; this package was building ok
everywhere when it was last uploaded (a long time ago, september 2018),
but now fails on s390x.

It's a scientific computation package, and the build process consists
in essentially three steps :
- build the source ;
- build the documentation, running the executables from the previous
step to show off their use ;
- run the checks, by running the executables from the first step on
stranger inputs, stressing the corner cases.

The buildd managed went through the first two steps, but only a few
tests ran, and already with a few failures (already a problem), until
one of them had to be killed after a while, presumably because it was
stuck (complete story here:
https://buildd.debian.org/status/fetch.php?pkg=giac&arch=s390x&ver=1.5.0.85%2Bdfsg1-1&stamp=1579706992&raw=0
).

I wanted to work on it and get meaningful data for upstream, so turned
to zelenka, the porterbox for this architecture. I followed the
tutorial here https://dsa.debian.org/doc/schroot/ - as I'm already used
to do when I get problems with other packages. But this time, the
documentation step already fails :
  ***   bug in PARI/GP (Segmentation Fault), please report.
(repeated quite a few times before the compilation dies)

I don't understand why I get so wildly different outcomes with the same
source package : did something get into unstable and break things
between the time the buildd ran and the time I tried to reproduce the
issue ? Do you have any advice ?

Thanks,

JP

Reply | Threaded
Open this post in threaded view
|

Re: Problems with the giac package : different failures on buildd and porterbox !?

Julien PUYDT-2
Le mercredi 22 janvier 2020 à 21:29 +0100, Julien Puydt a écrit :

> I wanted to work on it and get meaningful data for upstream, so
> turned
> to zelenka, the porterbox for this architecture. I followed the
> tutorial here https://dsa.debian.org/doc/schroot/ - as I'm already
> used
> to do when I get problems with other packages. But this time, the
> documentation step already fails :
>   ***   bug in PARI/GP (Segmentation Fault), please report.
> (repeated quite a few times before the compilation dies)
>

The compiled calculator gives strange results:
0>> 1/2.0-1/3
5.46834151467e-304
// Time 0
1>> 1/2.0
3.64556100978e-304
// Time 0
2>> 1/3
1/3
// Time 0
3>> 1/1.
3.64556100978e-304
// Time 0
4>> 1.
3.64556100978e-304
// Time 0

The last example shows that it's not just a computation problem.

There's something extremely fishy on that box!

JP

Reply | Threaded
Open this post in threaded view
|

Re: Problems with the giac package : different failures on buildd and porterbox !?

Aurelien Jarno
On 2020-01-23 07:52, Julien Puydt wrote:

> Le mercredi 22 janvier 2020 à 21:29 +0100, Julien Puydt a écrit :
>
> > I wanted to work on it and get meaningful data for upstream, so
> > turned
> > to zelenka, the porterbox for this architecture. I followed the
> > tutorial here https://dsa.debian.org/doc/schroot/ - as I'm already
> > used
> > to do when I get problems with other packages. But this time, the
> > documentation step already fails :
> >   ***   bug in PARI/GP (Segmentation Fault), please report.
> > (repeated quite a few times before the compilation dies)
> >

s390x is a big-endian architecture. The build failure on ppc64 and
sparc64 are really similar, so I believe the issue is related to
endianness.

> The compiled calculator gives strange results:
> 0>> 1/2.0-1/3
> 5.46834151467e-304
> // Time 0
> 1>> 1/2.0
> 3.64556100978e-304
> // Time 0
> 2>> 1/3
> 1/3
> // Time 0
> 3>> 1/1.
> 3.64556100978e-304
> // Time 0
> 4>> 1.
> 3.64556100978e-304
> // Time 0
>
> The last example shows that it's not just a computation problem.

That behaviour clearly shows that what is displayed is not the result of
the computation.

--
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
[hidden email]                 http://www.aurel32.net