The `finally` stops QEMU on every path the script controls, but not when
the script itself is killed -- a CI timeout, Ctrl-C at the wrong moment,
pkill. QEMU then keeps running with no parent. Because these tests run
under TCG rather than KVM, a spare emulator pinning a core slows every
later run, and one was found still executing the guest at 86% of a core
eight minutes after its parent was gone.
That is the bad kind of failure: the suite does not break, it gets
slower, and commands drift past Wait-Prompt's timeout until the next one
is typed into a busy shell and the transcript interleaves. The check
that then fails is unrelated to whatever actually changed.
Record the pid on startup and reap the previous run's leftover before
starting a new one, the same self-healing approach already used for the
monitor port. The name is checked before killing, because pids are
recycled and killing an unrelated process would be worse than the leak.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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