fix(hookify): fall back to __file__ when CLAUDE_PLUGIN_ROOT is unset

[adelaidasofia]

Problem

The four hook scripts in plugins/hookify/hooks/ depend on CLAUDE_PLUGIN_ROOT to add the plugin directory to sys.path so they can import core.config_loader and core.rule_engine:

PLUGIN_ROOT = os.environ.get('CLAUDE_PLUGIN_ROOT')
if PLUGIN_ROOT and PLUGIN_ROOT not in sys.path:
    sys.path.insert(0, PLUGIN_ROOT)

try:
    from core.config_loader import load_rules
    from core.rule_engine import RuleEngine
except ImportError as e:
    error_msg = {"systemMessage": f"Hookify import error: {e}"}
    print(json.dumps(error_msg), file=sys.stdout)
    sys.exit(0)

In some contexts Claude Code does not set CLAUDE_PLUGIN_ROOT on the subprocess it spawns for the hook. When that happens the imports fail, the script emits a systemMessage, and PreToolUse defaults to BLOCK, silently blocking every Write, Edit, and Bash call for the session.

I hit this reliably in git worktree sessions and some subagent contexts. The error the user sees is:

Hookify's own import is broken (No module named 'core'), which Claude Code treats as a block.

Even with sys.exit(0), the non-empty systemMessage and failed import are enough for the host to treat the PreToolUse hook as failed.

Fix

Since the script already knows its own location, it can derive the plugin root from __file__ as a fallback. The env-var path still takes precedence, so existing behavior is preserved.

PLUGIN_ROOT = os.environ.get('CLAUDE_PLUGIN_ROOT') or os.path.dirname(
    os.path.dirname(os.path.abspath(__file__))
)
if PLUGIN_ROOT not in sys.path:
    sys.path.insert(0, PLUGIN_ROOT)

Same pattern applied to all four hook scripts (pretooluse.py, posttooluse.py, stop.py, userpromptsubmit.py).

Verification

All four scripts return {} and exit 0 when piped stdin input with CLAUDE_PLUGIN_ROOT unset:

$ for f in pretooluse posttooluse stop userpromptsubmit; do
    echo '{"tool_name":"Write","tool_input":{}}' | python3 plugins/hookify/hooks/$f.py
  done
{}
{}
{}
{}

Before the patch the same commands produced {"systemMessage": "Hookify import error: No module named 'core'"}.

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