The BLOCK rule named "Filesystem root destruction" did not block the bare
root target it is named for. The target alternation ended in a shared `\b`,
and a word boundary cannot hold after `/` or `~` at end-of-command.
Measured against the shipped pattern:
bare `/` target NOT blocked `$HOME` target blocked
bare `~` target NOT blocked `/usr` target blocked
`/*` glob target NOT blocked
swapped flags (-fr) NOT blocked
sudo-prefixed NOT blocked
Only targets whose first character is a word character ever satisfied the
assertion, so the rule caught `/etc` but not bare root. These fell through
to WARN (exit 0) — advisory only, command executed.
- Pattern: `\b` moved onto the `$HOME` alternative alone, where it is
meaningful (it ends in a word char, so `$HOMEDIR` is still not
swallowed). Dropped from `/` and `~`. Nothing else changes: `/etc`,
`/home`, `./build` behave exactly as before.
- The old test file encoded this defect as expected behaviour, with a NOTE
claiming the pattern "requires separate flag groups (e.g. -f -r, not -rf
combined)". That diagnosis was wrong — the `/etc` case blocks fine with
merged flags. Comment replaced with the real root cause.
npm test: 1872/1872 green (1865 + 7 new).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TcQyMTQfyrsAapaCMPxTtQ