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<civodul>--check is bound to fail, at least because of the reproducibility bug

<rekado>civodul: that was my conclusion when I did a reproducibility analysis of pigx-sarscov2-ww, yes.

<rekado>annoyingly, I can’t seem to find my emails about this

<zimoun>civodul, Yes for sure. But it fails with getarch_2nd.c:12:35: error: ?SGEMM_DEFAULT_UNROLL_M? undeclared

<zimoun>What annoys me is the weirdness. On machine A, «guix time-machine --commit=4b1538e6ef -- help» fails and it passes on machine B. Bah, I do not know.

*rekado runs “guix time-machine --commit=87e7faa2ae641d8302efc8b90f1e45f43f67f6da -- build openblas”

<rekado>still building

<rekado>build phase complete

<rekado>all done

<zimoun>rekado: x86_64, right?

<zimoun>on foreign distro or Guix System?

<rekado>on Guix System, x86_64

<rekado>I sent a reply with the output of lscpu

<rekado>I’ll try again on a different server, foreign distro, with Intel(R) Xeon(R) CPU E7-4870 v2 @ 2.30GHz

<rekado>(I have to move .config/guix/channels.scm out of the way)

<zimoun>for 7357b3d7a52eb5db1674012c50d308d792741c48, It works for Intel(R) Xeon(R) Gold 5218 CPU @ 2.30GHz but not for Intel(R) Core(TM) i7-10700K CPU @ 3.80GHz; running both on Ubuntu (not the same version though)

<rekado>on that machine I just got a substitute

<rekado>will do “--check --no-grafts” to see if the build fails early

<rekado>it’s now building

<zimoun>Yes, I got the substitute too, and the failure is --check, --no-grafts.

<rekado>quickly!

<rekado>if this was like Konrad’s case it would have failed by now

<rekado>does Konrad’s failure happen on a CPU that is unknown by the old openblas because it is too recent?

<rekado>wow, the build is done

<zimoun>I do not know.

<rekado>of course “--check” failed, because the output differs

<zimoun>bah it is probably the CPU. For 87e7faa2ae641d8302efc8b90f1e45f43f67f6da, it passes on Intel(R) Xeon(R) Gold 5218 CPU @ 2.30GHz but fails on Intel(R) Core(TM) i7-10700K CPU @ 3.80GHz.

<rekado>so… running the build in qemu… is that still reproducibility or is it silly?

<zimoun>I do not know.

<zimoun>civodul, rekado: I have recently read the Skylake bug about OCaml http://gallium.inria.fr/blog/intel-skylake-bug/

<zimoun>is it possible for something similar for GCC?

<civodul>i pushed a couple of tweaks to the Guix-HPC report

<civodul>the term "open science" had to be present

<rekado_>oh?

<civodul>in the sense that it's good to relate our geeky work to the broader context

<civodul>(i hate this tendency to qualify anything as "open", it's meaningless, but hey)

<rekado_>ah

<rekado_>I thought you meant it didn’t pass some external PR threshold

<civodul>heh no :-)

<zimoun>hi!

<zimoun>civodul: the report LGTM! Even, all the achievements are great! :-)

<civodul>zimoun: hi! good, thanks for checking!

<civodul>i'll put it online after lunch

<rekado_>thank you!

<zimoun>civodul: how do I know the codename of cpu for --tune?

<zimoun>For instance, lscpu provides me the nam ei7-10700K but then I am going to https://ark.intel.com/content/www/us/en/ark/products/199335/intel-core-i710700k-processor-16m-cache-up-to-5-10-ghz.html to know that the product is formerly Comet Lake.

<zimoun>Then https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html does not list Comet Lake. Does it mean the CPU is not supported?

<civodul>zimoun: you can try the "guix shell cpuinfo -- cpu-info"

<civodul>or just run "guix build --tune gsl -n" for instance

<civodul>but yes, different compilers support different CPUs

<zimoun>Arf, I do not understand all this business… cpu-info tells me: Microarchitectures: 8x Sky Lake. But the official Intel doc calls it Comet Lake.

<zimoun>And “guix build --tune gsl -n” says «guix build: tuning gsl@2.7 for CPU broadwell».

<zimoun>Pic et pic et colegram ;-)

<civodul>is it a brand new Intel CPU?

<civodul>-> https://hpc.guix.info/blog/2022/02/guix-hpc-activity-report-2021/

<rekado_>yay!

<rekado_>pages 25, 26, and 27 are a breeze to read!

<rekado_>“We gave demonstrations of what Guix brings to scientific workflows are now available and we expect to continue to show that reproducible scientific workflows are indeed a possibility” — the “are now available” feels out of place

<civodul>ah damn it

<zimoun>civodul: I do not know if the CPU is new. The machine is recent, from December. It is 10th generation when Tiger Lake is 11th; and Tiger Lake is listed.

<civodul>rekado_, zimoun: could you make sure your institutes retweet or somehow relay the info?

<civodul>rekado_: oh yes, the blank pages are needed for the printed A5 booklet

<civodul>i recommend printing it, you'll see!

<civodul>and, as a bonus, it lets recipients of the printed copy take notes about their favorite parts

<rekado_>civodul: I’ll ask Altuna to tweet it; usually the comms department retweets then

IRC channel logs

2022-02-03.log