Round 3 review: two P1 asynchronous-correlation defects, with the
focused suite at 25/25 while both were live.
**1. A late version verdict retired nothing and claimed success.**
`probe.watching` is cleared the moment the server initializes — it is
failure-polling state. A slow `lake --version` landing after a
successful initialize therefore reached `fire_latch(nil)`, which retires
nothing: `_attach_buffer` found the still-live primary attachment,
early-returned it, and the retry counted that as done. Status said
"falling back", the config named the fallback, and the buffer stayed on
the old server.
**That is the round-1 silent no-op arriving through a third event
ordering** — first as "no re-attach at all", then as "re-attach cleared
by an unrelated buffer", now as "re-attach satisfied by the server we
were supposed to replace". The fix separates the two facts that were
being carried by one field: `probe.primary` is the server the verdict
applies to and survives initialization; `probe.watching` is the
failure poll and is cleared by it.
The existing fixture could not reach this ordering at all — its `serve`
sleeps, so the primary can never initialize before `--version` returns.
The new one execs the fake LSP for `serve` and delays 0.6s before
reporting 3.0.0.
**2. `buf_key` was the most recently loaded Lean buffer.** Written on
every Lean `buffer.after-load`, so a second Lean file opened before the
verdict became the rebuild target while the latch still watched the
FIRST buffer's server. Target buffer and primary server are one fact and
are now armed together, exactly once. Both files in the new test share a
package, so mis-targeting shows up as a stranded buffer rather than as
two unrelated servers.
**3. The failure message hardcoded `lake serve`** after the latch became
command-agnostic, telling a user whose `my-lean-wrapper` failed to go
debug lake. `configured_command()` names what is actually configured,
arguments included.
**4. The ledger** now records all fifteen bites across the three rounds,
both prior review rounds' findings (the round-2 block was lost when an
earlier edit script aborted before writing), and the durable lesson.
That lesson, recorded for the handoff: **six tests across three rounds
were written, ran green, and pinned nothing** — caught only by biting.
The shapes are enumerated in the ledger; the rule is that a test is not
evidence until the mutation it targets has been shown to fail it. Two
of the six are subtle enough to be worth naming here: a bite that
RAISES is swallowed by the hook's pcall and "passes" for the wrong
reason, and a fixture whose `serve` sleeps cannot reach any ordering
where the primary comes up first.
Levi Neuwirth
73587b0e37