Review round 4, P2. A fix can invalidate a test that was never written.
Criterion 17 still specified the pre-round-2 world: remove
`set_round_trip_input` and the optimistic op "passes `ensure_writable()`
and mutates BOTH sides, silently, with no divergence to notice". That
was true while no Lua binding set `read_only`. Since
`set_generated_contents` does, the daemon refuses the op — so only the
frontend's own mirror mutates, and the copies diverge.
The gap matters precisely because 17 is unpinned. A real-GPU test
written to the old spec would hunt for a daemon-side edit that can no
longer occur and pass for the wrong reason, quietly readmitting the
round-2 regression through a test not yet built. The specification is
the artifact under review here, not the code.
Restated around unauthorized MIRROR mutation plus daemon refusal —
divergence — in all four places carrying the obsolete claim: the
criterion itself, the Q#TC6a heading, the acceptance-16 doc comment, and
the bite roster. The heading's "ONLY thing" now says what it is the only
thing FOR: the replica's own mirror. `docs/active-work.md` also still
described acceptance 16b as asserting `is_read_only()` is false, which
round 2 flipped.
Why round-trip input stays load-bearing rather than redundant, now
stated wherever the daemon guard is mentioned: a refusal arrives after
the frontend has already applied optimistically and painted. It buys
divergence instead of silent agreement; it does not prevent the mutation
the user is looking at.
Also recorded, after capturing it properly this time: the gate-run flake
in `cargo test --lib --features crdt` is
`process::tests::setsid_escapee_is_not_reaped_and_teardown_reclaims_readers`
(`active_reader_probe` -> None, "live runtime probe"), ~1 run in 5.
Pre-existing and unrelated — this branch does not touch
`src/process.rs`, the test passes 10/10 standalone and 2017/2017 at
`--test-threads=1`, and it is another instance of the known `drain_until`
trap: draining for `Started` also ticks, and a tick reaps the leader.
That also explains the unattributed "2 failed" run noted in round 2.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016gGQC6eqHJVbZJ5Hg7aLer
Levi Neuwirth
23c966cc31