NoSignal-OS/os updates/kernel-reboot-notify

kernel-reboot-notify

Symptom / gap

When nosignal-update (or any pacman -Syu/yay) installs a new kernel, nothing tells the user to reboot. The new kernel + modules are written to disk, but the old kernel keeps running — and its /usr/lib/modules/<running> dir has been replaced, so the live session can no longer load matching modules (USB, filesystems, etc. can fail to load on demand). On NoSignal this also means the freshly-built UKI isn't booted yet. The user only finds out when something breaks — or, with F4, when they reboot and the default entry drops to a TTY.

Fix

1. nosignal-reboot-check (→ ~/.local/bin): if the running kernel's modules dir is gone (the update replaced it), it writes a stamp ($XDG_STATE_HOME/nosignal/reboot-required), prints a yellow banner, and raises a critical desktop notification ("Kernel updated — reboot to load it (X → Y)"). It clears the stamp once the running kernel matches disk again.
2. 95-nosignal-kernel-reboot.hook (→ /etc/pacman.d/hooks): a PostTransaction Path hook on usr/lib/modules/*/vmlinuz that prints a reboot reminder in the pacman/yay output — so updates done outside nosignal-update warn too.
3. nosignal-update wiring: calls nosignal-reboot-check as its last step, so an interactive update ends with the reminder + notification.

The installer (install-kernel-reboot-notify.sh) does all three idempotently. The pacman-hook step needs root.

Optional (builder): re-warn at login until rebooted

Add nosignal-reboot-check to an exec-once (e.g. alongside nosignal-welcome in hypr-user.conf) so a pending reboot is re-surfaced each login while the stamp exists. Not included by default to avoid touching hypr-user.conf here.

Builder integration

Ship nosignal-reboot-check in the layer's bin, ship the pacman hook in the ISO, and add the one-line call to the canonical nosignal-update (the installer shows the exact insertion). Pairs with F4: until F4 is fixed the reboot notice tells the user to pick the UKI entry.

Verify

# simulate (don't actually remove modules): the helper keys off
# /usr/lib/modules/$(uname -r) — present now, so it's a no-op:
nosignal-reboot-check; echo "exit=$?"
# after a real kernel update it prints the banner + notifies and stamps
# ~/.local/state/nosignal/reboot-required

Files

• nosignal-reboot-check — detector + notifier.
• 95-nosignal-kernel-reboot.hook — pacman PostTransaction reminder.
• install-kernel-reboot-notify.sh — idempotent installer (hook step needs root).
• migrations/1781438400-kernel-reboot-notify.sh — delegates to it.