A SIGKILL leaves the sidecar behind, and the next run wrote it over whatever
the file then held. That is right after a kill and destructive after one: a fix
written to the source between the kill and the next run was reverted to bytes
from before the kill, with a line claiming a repair, and the run then reported
mutation results for code nobody had written.
The mutation table is the record of what a live run can leave behind: the
original (which is the sidecar, and also what the no-op control writes) or the
original with exactly one of that target's mutations applied. Repair now
recognises those and nothing else. A file matching neither stops the run with
its own digest and the sidecar's and changes nothing.
Reproduced both halves against the shared target. Killed mid-mutation, then
appended a line to the source: the rerun exits 1, prints both sha256s, and the
hand-written line is still there afterwards. With the mutant put back and the
sidecar unchanged, the rerun repairs as before and now names the mutation the
dead run was inside.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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