---
model: openai/gpt-5.6-sol
service: opencode
timestamp: 2026-08-18T19:30:02Z
git_ref: bf06b4f8
diff_cmd: git diff HEAD~1..HEAD
---

Repeated teardown sites reconstruct the `Actor._contexts` registry
key from a portal channel and context ID before popping it. Add an
idempotent actor-owned helper deriving the key from the context itself,
then route caller and callee context teardown through that helper.

> `git diff HEAD~1..HEAD -- tractor/runtime/_runtime.py tractor/runtime/_rpc.py tractor/_context.py`

Keep receive-channel closure and cancellation shielding in each
lifecycle owner so the helper centralizes registry machinery without
changing their teardown ordering.