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
