Four */lib/tests/run_all.sh runners existed — periodic_background, hosts,
single_use/utils and the new digital_wellbeing one — and no workflow ran any
of them. Every assertion the cap-split sessions wrote was executing only on
the author's machine.
Discovered rather than listed: each split adds another runner, and a
hardcoded list is what let the first four go unnoticed. The step fails if
discovery matches zero runners, so a future path change cannot quietly turn
this into a vacuous green step.
Verified by running the step's exact logic under bash: 4 runners discovered,
all exit 0. Checked for Arch-only dependencies first — the only `command -v`
probe in the harnesses is `unshare` (present on ubuntu-latest, and guarded),
and no suite touches pacman, chattr, systemctl or adb, so these belong in the
Ubuntu job rather than the Arch container.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01F3PzGc75gBcdxP3PkHXGcV
