canonical_number went from 29 missed to 4, all four hand-traced as equivalent
rather than assumed. is_canonical, the Q-J door whose every branch mutation
was surviving, had never been called directly by any test; it is now.
The finding that outlives the batch is infrastructural. The same commit gave
different missed and timeout sets across three -j4 runs, while every -j1 run
reproduced the same result, most likely the shared cargo target directory
under concurrent mutant builds. That makes every concurrent mutation figure in
this campaign provisional, Stryker's --concurrency 4 runs included. Killed
mutants stay killed; survivor lists from concurrent runs cannot be trusted as
complete, so the rulings they informed rest on the hand-confirmed evidence
beside them rather than on the counts.
A third test in two days passed by coincidence: render_f32's sign-bit mutant
survived because 1.0 and 2.0 happen to have bit 0 matching their sign bit.
contracts.rs and schema_discovery.rs remain unmeasured. A partial run showed
real misses across the validate family before it was killed; that signal is
recorded so the next pass starts from it. Queued rather than run, because the
merge gate is a Soul pass on batch 5, not a sweep of an adjacent file.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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