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Mathieu Benoit 92c5850e53 [FIX] driver: kill a build that has stopped producing output
python's PKGBUILD hunts for a free X display before running make:

  export servernum=99
  while ! xvfb-run -a -n "$servernum" /bin/true 2>/dev/null; do
      servernum=$((servernum+1)); done

xvfb-run is not installed here. It exits 127, `!` inverts that to true, and
the loop tries the next number. There is no exit condition for "the command
does not exist", and the 2>/dev/null swallows the one line that would have
said so.

Measured before anyone noticed: ten hours of wall clock, four million PIDs,
and a log frozen at `configure: creating Makefile`. Every signal said the
build was healthy -- alive, 40% CPU, sitting in a plausible source directory.
A process list cannot tell work from spinning. A stalled log next to a live
makepkg can, and that is all this guard does.

Forty-five minutes of COMPLETE silence, because real builds do go quiet: a
long link, a test suite that prints nothing, gcc between bootstrap stages.
The case this was written for ran two hundred times longer. EL_STALL_MIN=0
disables it.

Tested against a real spin loop: detected, whole process tree killed, rc=2 so
STALL reads differently from FAIL in the summary.

--- FR ---

Le PKGBUILD de python cherche un numéro d'affichage X libre avant make :

  export servernum=99
  while ! xvfb-run -a -n "$servernum" /bin/true 2>/dev/null; do
      servernum=$((servernum+1)); done

xvfb-run n'est pas installé ici. Il sort en 127, le `!` inverse, et la boucle
essaie le numéro suivant. Il n'existe aucune condition de sortie pour « la
commande n'existe pas », et le 2>/dev/null avale la seule ligne qui l'aurait
dit.

Mesuré avant que quiconque s'en aperçoive : dix heures d'horloge, quatre
millions de PID, un journal figé à `configure: creating Makefile`. Tous les
signaux disaient que le build allait bien — vivant, 40 % de CPU, dans un
répertoire source plausible. Une liste de processus ne distingue pas le
travail du sur-place. Un journal figé à côté d'un makepkg vivant, si — et
c'est tout ce que fait ce garde-fou.

Quarante-cinq minutes de silence COMPLET, car de vrais builds se taisent :
une longue édition de liens, une suite de tests muette, gcc entre deux étages.
Le cas qui l'a motivé a tourné deux cents fois plus longtemps. EL_STALL_MIN=0
le désactive.

Éprouvé contre une vraie boucle infinie : détecté, arbre de processus tué en
entier, rc=2 pour que STALL se lise autrement que FAIL dans le bilan.

Assisted-by: Claude Opus 5
2026-08-19 19:53:46 -04:00
.github/workflows making the house a home 2026-01-27 23:26:31 +01:00
arch-kernel making the house a home 2026-01-27 23:26:31 +01:00
boot making the house a home 2026-01-27 23:26:31 +01:00
patches [ADD] stage 2: the rebuild loop, and git to feed it 2026-08-19 08:56:41 -04:00
scripts [FIX] driver: kill a build that has stopped producing output 2026-08-19 19:53:46 -04:00
.env.example full boot with systemd 2025-06-05 12:32:34 +02:00
.gitignore making the house a home 2026-01-27 23:26:31 +01:00
CODEOWNERS making the house a home 2026-01-27 23:26:31 +01:00
Containerfile making the house a home 2026-01-27 23:26:31 +01:00
LICENSE use arch kernel patches 2025-06-02 21:53:33 +02:00
Makefile making the house a home 2026-01-27 23:26:31 +01:00
README.md making the house a home 2026-01-27 23:26:31 +01:00
TODO.md [FIX] test-chroot: an audit that classifies, and one that was wrong 2026-08-19 06:40:50 -04:00

Arch Linux s390x

A port of Arch Linux to IBM s390x mainframe architecture with systemd support.

Boots a full Arch Linux system on IBM mainframes (or QEMU s390x emulation) using a hybrid build: cross-compilation for the kernel, native s390x compilation on z/VM for userspace.

Quick Start

make container        # build dev container (first time)
cp .env.example .env  # configure z/VM access
make all              # build kernel + initramfs + systemd
make test-systemd     # boot it

What Works

  • Arch Linux kernel 6.18.6-arch1 with Arch patches, cross-compiled
  • Initramfs via modified mkinitcpio
  • Static busybox built natively on z/VM, 2.3MB
  • Root filesystem with ext4, switch_root to real rootfs
  • Systemd as PID 1

Pacman, bash, and GNU coreutils are not yet ported.

Build System

The build uses two tiers:

Cross-compilation (x86_64 host): Kernel is built in a Fedora 43 container with s390x-linux-gnu-gcc. Initramfs is generated with a patched mkinitcpio that handles cross-architecture binary injection.

Native compilation (s390x z/VM): Busybox and systemd must be built on real s390x hardware. The z/VM system runs RHEL 9.6 with GCC 11.5.0. Scripts handle SSH deployment and retrieval automatically via .env configuration.