ugrep: reproducibility issues

Hi, I found another package, ugrep, which is evidently using native

instructions that do not work on my processor. When I run ugrep (e.g.,

`ugrep -Q') it immediately dies with error 'illegal instruction'.

However, if I pull the source with `guix build -S' and build and

install it to a local directory, it runs without trouble.

I'm sure this will also be a reproducibility bug, and plan on

submitting guix challenge results. However, the command I am running to

rebuild ugrep without grafts or substitutes is rebuilding everything

all the way back to bootstrap, so it probably will not be completed for

a day or two:

guix gc -D $(guix build --no-grafts ugrep); guix build --no-substitutes

ugrep

Please compare similar bug 48373. It didn't seem worth the trouble of

running an object dump and figuring out which instruction is illegal,

but I could do that if required.

My system information:

christopher@nightshade ~$ grep 'flags' /proc/cpuinfo | head -n 1

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge

mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext

fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl

nonstop_tsc cpuid extd_apicid pni monitor cx16 popcnt lahf_lm

cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch

osvw ibs skinit wdt hw_pstate vmmcall npt lbrv svm_lock nrip_save

christopher@nightshade ~$ neofetch --stdout

christopher@nightshade

----------------------

OS: Guix System d4ffa9630277fa8699c783c08381d688626d4bc3 x86_64

Host: GA-880GM-UD2H

Kernel: 5.12.5-gnu

Uptime: 1 hour, 30 mins

Packages: 107 (guix-system), 93 (guix-user)

Shell: bash 5.0.16

Resolution: 1920x1200

DE: GNOME 3.34.5

Theme: Adwaita [GTK2/3]

Icons: Adwaita [GTK2/3]

Terminal: kitty

CPU: AMD Athlon II X3 455 (3) @ 3.300GHz

GPU: NVIDIA GeForce 8400 GS Rev. 3

Memory: 1573MiB / 7957MiB

christopher@nightshade ~$ guix describe

Generation 5 May 22 2021 09:43:30 (current)

guix d4ffa96

repository URL: https://git.savannah.gnu.org/git/guix.git

branch: master

commit: d4ffa9630277fa8699c783c08381d688626d4bc3

--

Christopher Howard

blog: https://librehacker.com

social: https://gnusocial.club/librehacker

christopher@nightshade ~$ guix challenge ugrep

/gnu/store/a6x7rv7xi3d2pw205znmnha9qfjrvs7k-ugrep-3.1.12 contents

differ:

local hash: 1yf9752hprihmhwnqlhaffkmwmkd3scwzr8dqy7d78vcy70qjkn6

: 1ifdjmscb07pacxwcs2408zi12yrxxf0zdwzz800xlccp5x53m7r

differing file:

/bin/ugrep

1 store items were analyzed:

- 0 (0.0%) were identical

- 1 (100.0%) differed

- 0 (0.0%) were inconclusive

--

Christopher Howard

blog: https://librehacker.com

social: https://gnusocial.club/librehacker

On Sat, May 22, 2021 at 12:19:30PM -0800, Christopher Howard wrote:

Do this instead:

$ guix environment --no-grafts ugrep -- guix build --no-grafts --no-substitutes ugrep

That way, you can use substitutes for ugrep's dependencies, but then

build ugrep from source.

I hope it helps!

On Mon, 24 May 2021 13:22:23 -0400

Leo Famulari <leo@famulari.name> wrote:

TIL about that. There really ought to be a more obvious way to do that.

On Wed, Jun 30, 2021 at 11:41:11PM +0200, raingloom wrote:

Agreed! It's a common use case.

Hi,

On Sat, 22 May 2021 at 12:19, Christopher Howard <christopher@librehacker.com> wrote:

Indeed, the package ’ugrep’ is not reproducible:

guix build ugrep --no-grafts -q

guix build ugrep --no-grafts -q --check -K

diff --no-dereference -r /gnu/store/a6x7rv7xi3d2pw205znmnha9qfjrvs7k-ugrep-3.1.12{,-check}

Binary files /gnu/store/a6x7rv7xi3d2pw205znmnha9qfjrvs7k-ugrep-3.1.12/bin/ugrep and /gnu/store/a6x7rv7xi3d2pw205znmnha9qfjrvs7k-ugrep-3.1.12-check/bin/ugrep differ

The next step is to investigate with diffoscope.

Well, another data point – maybe Berlin has an issue – because I get:

guix challenge ugrep --substitute-urls="https://ci.guix.gnu.orghttps://bordeaux.guix.gnu.org"

/gnu/store/a6x7rv7xi3d2pw205znmnha9qfjrvs7k-ugrep-3.1.12 contents differ:

local hash: 1ifdjmscb07pacxwcs2408zi12yrxxf0zdwzz800xlccp5x53m7r

https://ci.guix.gnu.org/nar/lzip/a6x7rv7xi3d2pw205znmnha9qfjrvs7k-ugrep-3.1.12:1ifdjmscb07pacxwcs2408zi12yrxxf0zdwzz800xlccp5x53m7r

https://bordeaux.guix.gnu.org/nar/lzip/a6x7rv7xi3d2pw205znmnha9qfjrvs7k-ugrep-3.1.12:1yf9752hprihmhwnqlhaffkmwmkd3scwzr8dqy7d78vcy70qjkn6

guix hash -r $(guix build --no-grafts ugrep)-check

1yf9752hprihmhwnqlhaffkmwmkd3scwzr8dqy7d78vcy70qjkn6

I fetch by default the substitutes from ci that why “local hash“ and ci

are the same; but my local build with ‘guix build --check’ gives the

same hash as bordeaux.

All the best,

simon

retitle 48591 ugrep: reproducibility issues

quit

Is this bug fixed yet?

If not, seeing that this issue was motivated by an illegal instruction,

we can use compile flags to disable SSE and other platform-dependent

optimizations and investigate further.

WDYT?