On Tue, Jul 24, 2018 at 08:43:02PM +0200, Christoph Biedl wrote:
> Adrian Bunk wrote...
>
> > I'd like to get a clear picture regarding the situation of building
> > armel for buster on arm64, ideally moving it to arm64 hardwre soon.
>
> JFTR, I'd appreciate if armel/armhf could continue to be part of a
> release.
>
> > 1. What issues are considered possible problems for moving building
> > armel from 32bit v7 hardware to 64bit v8 hardware?
>
> Perhaps just babble and FUD: There was (and probably still is) an issue
> in powerpc: In a certain package, upstream's compile options for ppc had
> higher CPU requirements than what Debian uses for that architecture. As
> a result, the buildd (some big IBM POWER box) happily built the package,
> but out there on a G4 the code would crash for SIGILL, same when
> rebuilding on such a hardware.
>
> Now I'm somewhat afraid this might happen again when packages for
> armel/armhf are built on more recent hardware. At the same time, I'd
> like to see continued support for these architectures.
>
> If this is a concern, how to solve it? Have some native non-DSA
> armel/armhf boxes where volunteers rebuild the archive and hope test
> suites will catch such issues?
This is not really a concern for a v7 -> v8 build change for armel.
stretch has a v4 baseline and v7 buildds.
buster has a v5 baseline.
I am not saying that baseline violations don't happen on armel (they do),
just that this change is unlikely to make a difference here.
For armhf this is actually a valid concern, especially regarding NEON.
NEON is not in the armhf baseline, and since our current buildd hardware
does not support NEON this catches plenty unconditional NEON usage.
One option for mitigating this problem would be to repurpose one
or more of the current buildd machines (there is even a spare)
for debci.
(Trying to use NEON on armel will give a compile error in any case.)
> My 2ยข
>
> Christoph
cu
Adrian
--
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed
