Re: Investigating a reproducibility failure

[Konrad Hinsen <konrad.hinsen@fastmail.net>]

Hi Ricardo and Simon,

Ricardo Wurmus <rekado@elephly.net> writes:

> The case of OpenBLAS is an anomaly in that this mechanism seems to
> produce different binaries dependent on where it is built.  When I first

Thanks a lot for those explanations, I hadn't realized how peculiar
OpenBLAS is!

> Your problem is that the OpenBLAS build system doesn’t recognize your
> modern CPU.  Ideally, it wouldn’t need to know anything about the
> build-time CPU to build all the different code paths for different CPU
> features.  The only way around this — retroactively — is to pretend to
> have an older CPU, e.g. by using qemu.

So all we need is a "QEMU build system" in Guix, just for OpenBLAS ;-)

> The new “--tune” feature is supposed to take care of cases like this.

Right, I remember Ludo's blog post about this.


zimoun <zimon.toutoune@gmail.com> writes:

> Somehow, “recent” processors cannot build old versions.

That's a whole new level of planned obsolescence!

Cheers,
  Konrad.