setup_hosts_guard.sh died partway on every run under `set -euo pipefail`,
which is why hosts-guard.path / hosts-bind-mount.service / nsswitch-guard.path
sat installed-but-disabled since 2026-02-02 and resolved-guard.path was never
installed at all — /etc/hosts had no watcher to restore it if tampered.
Two aborts, both silent:
1. `local_dot=$(grep -E '^\s*DNSOverTLS\s*=' ... | tail -1 | sed ...)` — grep
exits 1 when the key is absent, pipefail propagates, the assignment returns
1, set -e kills the script. DNSOverTLS is absent from a default
resolved.conf, so this fired on EVERY run, right before resolved-guard.path
was enabled. The fix-if-missing branch below it was unreachable because
detecting "missing" aborted first. Same trap on the ReadEtcHosts probe.
check_and_enable_services.sh already guarded its copy with `|| true`.
2. `systemctl restart systemd-resolved` — resolved is MASKED here (dnsmasq
serves DNS), so the restart failed and aborted the script on its last step,
after everything was already configured. Now skipped with a note.
Before: exit 1, resolved-guard disabled, nsswitch-guard start-limit-hit.
After: exit 0; hosts-guard.path, hosts-bind-mount.service, nsswitch-guard.path
and resolved-guard.path all enabled+active. DNS still resolves; getent ahosts
on doubleclick/googlesyndication/facebook returns 0.0.0.0; /etc/hosts still
immutable at 176888 lines.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JsCs1GUyiinA7bg68YvAh1
Replaces the bespoke chattr/bind-mount/systemd-watcher implementations for
/etc/hosts and /etc/shutdown-schedule.conf with the new shared guard-lib
(~/guard-lib, guardctl), so screen-locker and steam-backlog-enforcer's new
block-gaming feature stop maintaining parallel copies of the same
tamper-resistance mechanism.
- pacman_wrapper.sh: pre/post hook fallbacks now call guard-lib's generic
unlock-all/relock-all scripts (covers every registered guard instance,
not just /etc/hosts)
- setup_midnight_shutdown.sh: installs/updates its guarded config via
guardctl file-guard instead of hand-rolled chattr + systemd unit
generation; the schedule ratchet logic (block-if-more-lenient) stays
bespoke since guardctl's generic unlock can't represent it
- new hosts/guard/plugins/nsswitch-plugin.sh, resolved-plugin.sh
Also fixes, at user's request even though pre-existing: 3 shellcheck
SC2329 false positives in pacman_wrapper.sh (functions invoked indirectly
by name, not actually dead) and 1 SC2001 style warning (echo|sed VM-name
extraction replaced with parameter expansion, verified equivalent output).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AFNiYQQgSLAkiBXswyimPq
