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