The original hook syntax `blue guard --path="$TOOL_INPUT:file_path"`
didn't work - Claude Code doesn't support that variable interpolation.
Created guard-write.sh that:
- Reads JSON from stdin using jq (Claude Code's recommended pattern)
- Extracts file_path from tool_input
- Calls blue guard with full path to target/release binary
- Closes stdin with </dev/null to prevent hanging
The full binary path is a workaround for an issue where PATH-based
command lookup hangs in Claude Code's hook subprocess environment.
A proper fix (making guard synchronous before tokio::main) is tracked
in RFC 0049.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
