The cut does not close. The lifetime model was right in shape and wrong by
one line: the last call notifies after it has released the lock, so the
runtime can be destroyed in between and the wake lands on freed memory. A
sanitizer found it on the unmutated bridge.
The mutation that survived by construction is ruled killable rather than
accepted. Under a sanitizer with pollers blocked mid-copy it fails four times
in forty-eight, so a dev-only assertion makes it fail every time instead. Two
further mutations are honest only on the sanitizer target and the table must
say so, because a mutation whose kill depends on the target is not killed
until it runs there.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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