attune/work-summary/2026-02-20-sensor-runtime-upsert-fix.md

Fix: Python Sensor "Permission Denied" — Stale Runtime Assignment

Date: 2026-02-20

Problem

Python-based sensors failed to start with Permission denied (os error 13).

Root Cause

The sensor's runtime in the database pointed to core.builtin (empty execution_config) instead of core.python. This caused is_native=true, making the sensor manager try to execute the .py script directly — which fails without the execute bit.

The stale assignment persisted because the pack component loader skipped existing sensors on re-registration instead of updating them. Once a sensor was created with the wrong runtime, there was no way to correct it short of deleting the pack entirely.

DB evidence: SELECT runtime, runtime_ref FROM sensor → runtime=4, runtime_ref=core.builtin (should be runtime=3, runtime_ref=core.python).

Changes

1. Sensor upsert on re-registration (crates/common/src/pack_registry/loader.rs)

• Changed load_sensors from skip-if-exists to upsert: existing sensors are updated with fresh metadata from the YAML (runtime, entrypoint, trigger, config, etc.)
• Re-registering a pack now corrects stale runtime assignments

2. UpdateSensorInput extended (crates/common/src/repositories/trigger.rs)

• Added runtime, runtime_ref, trigger, trigger_ref, and config fields so the update path can correct all sensor metadata
• Updated all callsites in crates/api/src/routes/triggers.rs and tests

3. Registration-time validation (crates/common/src/pack_registry/loader.rs)

• Warns if a non-native runner_type (e.g., python) resolves to runtime ID 0 (not found)
• Warns if the resolved runtime has empty/missing execution_config

4. Sensor manager diagnostics (crates/sensor/src/sensor_manager.rs)

• Logs full runtime details (id, ref, name, raw execution_config JSON)
• Logs env_dir_exists status and resolved interpreter path
• Pre-flight check: verifies binary exists and has execute permission before spawn
• Error message includes binary path, is_native flag, and runtime ref

5. Python loader consistency (scripts/load_core_pack.py)

• Added runtime and runtime_ref to sensor ON CONFLICT DO UPDATE clause

Verification

After rebuilding and re-registering the pack with force=true:

• Sensor runtime corrected: core.builtin → core.python
• Sensor started successfully with venv interpreter at /opt/attune/runtime_envs/python_example/python/bin/python3
• Counter sensor fully operational (RabbitMQ connected, rules bootstrapped)