docs(framing): revision 4 --- and the failure has a datable onset

Four findings on revision 3, all upheld. Answering finding 1 turned up
something that reframes the lane.

THE ONSET. sweep-crdt appears SEVENTEEN times in this target directory's
gate logs. The ctrl_c failure appears in exactly the LAST THREE, and the
test passed --- both copies, "... ok" --- inside the stage before them.
Last green 20260815T185708Z, first red 20260816T063330Z, no reboot
between. The three earlier red sweeps failed on unrelated rows. So
"pre-existing on main" holds (F1 at 72da24a reproduces it) but "always
broken" was never established and is now contradicted. D0 gains a first
part: bisect that window. A test that passed fourteen times in this
stage and then failed three times running has a change behind it, and
that is worth more than further reduction --- which has isolated
nothing.

1. Both ledgers still carried the falsified R9 conclusions. This branch
   listed --workspace unification and preceding tests as ruled out
   while the section above described an interaction; said "five call
   sites" immediately before correcting to six; and labelled the
   framing revision 2. The held branch was worse: --workspace refuted,
   R9 "same binaries", later packages not implicable, cause cumulative
   across 37 binaries. All corrected and pushed (5b9abd8). §11 no
   longer asserts the held lane is clean; it records a re-verified
   checklist, since asserting that prematurely is what went wrong.

2. Manifest now carries complete argv for R7-R9 and F5 --- abbreviations
   are not reconstructable invocations. F5 is disambiguated: the
   framing cited gate ...-2144707 while the manifest cited ...-2375685,
   two distinct real runs. Enumerating them gives F1-F7: the red count
   is SEVEN, not five, each with its own log digest. F5 also carries an
   extra failing binary the others do not.

3. "Workspace artifact family" conflated Cargo suffix with byte
   identity and is withdrawn as a grouping. Demonstrated: F1 in the
   main worktree executed the same suffixes -5d9105cb and -d4dae4f0,
   but the bytes there are e0578039/00f06aeb versus the panel
   worktree's 1b3cc86c/ede0c07d. Each run now records the suffix its
   log shows and byte identity as UNKNOWN, since target dirs have been
   overwritten and a hash computed today is not the hash that ran.

4. The interaction table is demoted to a description of what was
   observed. Revision 3 disclaimed its inputs and then asserted a
   finding from them, which cannot both hold. A3 no longer speaks of an
   established "R9 paradox" --- there is none to explain, because the
   comparison was never made; it requires D0 to recreate it first.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai

docs/active-work.md

@@ -279,10 +279,11 @@ from #171 and #215.
   **`72da24a`**, worktree
   `/home/jeans/Repos/personal/pmacs-probe-sigint`. Recover with
   `git fetch githubsucks && git checkout gpu-probe-sigint-teardown`.
-- **No PR. Framing revision 2 at `docs/gpu-probe-sigint-framing.md`;
+- **No PR. Framing revision 4 at `docs/gpu-probe-sigint-framing.md`;
   NO IMPLEMENTATION and no fix proposed** — the mechanism is not known
-  yet, and the framing says so rather than guessing. Revision 1 was
+  yet, and the framing says so rather than guessing. Revisions 1, 2 and
-  rejected on five findings, all upheld.
+  3 were each rejected on findings, all upheld; run provenance lives in
+  `docs/probe-sigint-evidence.md`.
 - **Why it exists.** `ctrl_c_on_launcher_group_does_not_reach_spawned_daemon`
   fails in gate stage `sweep-crdt` with "child did not exit within 5s".
   **Pre-existing on `main`** — `72da24a` fails it in a clean worktree
@@ -311,8 +312,11 @@ from #171 and #215.
   "their targets execute after the failure" does not exonerate them.
 - **Ruled out by measurement — do not re-run:** machine load; tmpfs
   starving RAM (settled by experiment, not argument — `/tmp` 21G→1.2G,
-  available 27G→45G, still red); leaked daemons; inotify;
+  available 27G→45G, still red); leaked daemons; inotify.
-  `--workspace` feature unification; any specific preceding test.
+- **NOT ruled out, contrary to earlier entries here:** `--workspace`
+  artifact selection, and the preceding tests. R9 appeared to clear
+  them but ran **different binaries**, so the comparison was never
+  made. Both are open.
 - **Ground truth, and what it does NOT establish.** Neither binary
   contains signal-handling code: `run_gpu` (`src/main.rs:324`) blocks
   in `command.status()` with no handler, and grepping all of
@@ -333,9 +337,9 @@ from #171 and #215.
   about **5.1s** — inside what the sampler saw, and a ">6s" selector
   would have captured nothing, repeating the error it was meant to
   correct. (a) is therefore not refuted by (b); it stays **unproven for
-  a different reason** — the suite spawns launchers from five call
+  a different reason** — under `--features crdt` the suite spawns root
-  sites, so command line alone cannot attribute one to this test.
+  launchers from **six** call sites, so command line alone cannot
-  Under `--features crdt` that is **six** sites (`:509, :534, :544,
+  attribute one to this test. The six (`:509, :534, :544,
   :574, :725, :1097`, all inside `#[cfg(feature = "crdt")] mod crdt`);
   the other two `--gpu` arguments sit under `#[cfg(not(…))]` and are
   compiled out. **Do not key on process age. Key on the PID the test
@@ -362,10 +366,22 @@ from #171 and #215.
   machine-local under
   `/home/jeans/build/pmacs-gate-targets/probe-sigint-evidence/`; `/tmp`
   is a tmpfs and they were nearly lost to a cleanup mid-lane.
-- **D0 precedes every other diagnostic:** re-run the matrix at `main`
+- **THE ONSET IS DATABLE, and it reframes the lane.** `sweep-crdt`
-  under a harness that captures provenance **and the artifact hashes
+  appears **17 times** in this target dir's gate logs; `ctrl_c` fails
-  actually executed**, since command shape silently changed the binary
+  in exactly the **last three** and passed — both copies — before them.
-  once already.
+  Last green `20260815T185708Z`, first red `20260816T063330Z`, no
+  reboot between. The three earlier red sweeps failed on unrelated
+  rows. So "pre-existing on `main`" holds (F1 at `72da24a` reproduces
+  it) but **"always broken" is contradicted**.
+- **Red full-sweep count is SEVEN, not five** (F1–F7 in the manifest),
+  each with its own log digest; revision 3 said 5/5 while the framing
+  separately cited a gate run the manifest never listed.
+- **D0 precedes every other diagnostic**, in two parts: **(a) bisect
+  the onset window** — the sharpest lead the lane has; **(b)** re-run
+  the matrix at `main` under a harness capturing provenance **and the
+  artifact hashes executed at run time**, since command shape silently
+  changed the binary once already and a hash computed later reflects
+  only what occupies that path now.
 - **Coherence: journey step 12(a), "closing is clean", IS touched** —
   Ctrl-C teardown of a GPU session is that step, grade movement or not.
   Revision 1 claimed no journey step, reasoning from grade movement,

docs/gpu-probe-sigint-framing.md

@@ -1,6 +1,6 @@
 # GPU launcher / probe SIGINT teardown — framing
 
-Revision 3. Status: **awaiting approval. No implementation.**
+Revision 4. Status: **awaiting approval. No implementation.**
 
 Revisions 1 and 2 were each rejected on five findings. Every correction
 is recorded in place rather than quietly rewritten, because three of
@@ -14,6 +14,12 @@ them were claims this document itself had advanced:
   never blocks indefinitely" (§3); the launcher call-site count (§5);
   reduction provenance, now in `docs/probe-sigint-evidence.md`; and
   ledger corrections that had not been made portable (§11).
+- r3 → r4: the interaction table overstated (§4); the red count was 7,
+  not 5, and abbreviated argv were not argv (manifest); "workspace
+  artifact family" conflated Cargo suffix with byte identity
+  (manifest); ledgers still carried the falsified R9 conclusions (§11).
+  **And a finding that reframes the lane: the failure has a datable
+  onset (§4a) and is not long-standing.**
 
 ## 1. The problem, stated as what is observed
 
@@ -131,8 +137,11 @@ Cargo's target selection changes the fingerprint, so command shape
 changes the executable. R9 therefore establishes **same target names
 and order**, not same binaries.
 
-What the evidence actually supports is an **interaction**, and only
+What the evidence is **consistent with** is an interaction. It does not
-that:
+isolate one, because the three rows differ in more than the two columns
+shown — different source heads, different worktrees, unknown
+cleanliness, and, as above, different bytes behind identical Cargo
+suffixes:
 
 | prior targets execute | workspace artifact family | result |
 |---|---|---|
@@ -140,19 +149,50 @@ that:
 | no | yes | R10 green |
 | yes | yes | **F1–F5 red** |
 
-Neither factor alone reproduces it. So `--workspace` artifact
+Neither factor alone reproduced it **in these runs**. That is the
-selection is **not sufficient by itself** — and, importantly, **not
+whole of the claim. `--workspace` artifact selection is **not
-ruled out either**, which is how revision 2 phrased it. Later-selected
+sufficient by itself and not ruled out**; later-selected packages can
-packages can influence Cargo's build graph and fingerprints *before*
+influence Cargo's build graph and fingerprints *before* their test
-their test executables ever run, so "their targets execute after the
+executables run, so "their targets execute after the failure at line
-failure at line 3066" does not exonerate them. The same applies to the
+3066" does not exonerate them — that claim is withdrawn. And since
-claim that other packages "cannot be implicated": withdrawn.
+§4's own preamble says no historical row should be relied on until D0,
+**this table is a description of what was observed, not a finding**.
+Revision 3 asserted it as an interaction while simultaneously
+disclaiming its inputs, which cannot both be true.
 
 Also refuted, by measurement: machine load (red on a quiet box, load
 2.77); tmpfs starving RAM (**tested by experiment** — `/tmp` 21 G →
 1.2 G, available 27 G → 45 G, still red); leaked daemons (peak 58, +8
 per sweep, green runs already at 46–60); inotify (47 of 1024).
 
+## 4a. The onset is datable — and it reframes the lane
+
+`sweep-crdt` appears **17 times** in this target directory's gate logs.
+`ctrl_c` fails in **exactly the last three**, and passed — both copies,
+`... ok` — in the runs before them.
+
+| window | runs | `ctrl_c` |
+|---|---|---|
+| 08-14 → 08-15 19:57 | 14 (11 green; 3 red on *other* tests) | **passes** wherever the stage ran |
+| 08-16 06:33 `…-1977433` | red, 2 bins | **fails, both copies** |
+| 08-16 06:45 `…-2144707` | red, 2 bins | **fails, both copies** |
+| 08-17 17:25 `…-2375685` | red, 3 bins | **fails, both copies** |
+
+The three earlier red sweeps failed on unrelated rows — protocol and
+version tests, and `composition_overhead_under_ten_percent`. None
+involved `ctrl_c`.
+
+**So the failure is not long-standing.** "Pre-existing on `main`"
+remains true — F1 at `72da24a` reproduces it — but "always broken" was
+never established and is now contradicted. Last green containing it:
+`20260815T185708Z`. First red: `20260816T063330Z`. The machine was not
+rebooted across that boundary.
+
+**This supersedes the reduction matrix as the lane's first move.** A
+test that passed in this stage fourteen times and then failed three
+times running has a change behind it, and identifying that change is
+worth more than further reduction — which, per §4, has isolated nothing.
+
 ## 5. Two retracted claims, both mine, kept as warnings
 
 **Claim A — "mechanism located".** Reported the launcher blocked in
@@ -207,11 +247,14 @@ diagnostic only, and it must **discriminate** the three live candidates:
 blocked delivery, inherited ignore, and an escaped or wrong process
 group.
 
-- **D0 — re-run the §4 matrix with captured provenance**, at `main`,
+- **D0a — bisect the onset window** (§4a): `20260815T185708Z` green →
-  recording the artifact hashes actually executed. Revision 2's
+  `20260816T063330Z` red, no reboot between. This is the sharpest lead
-  strongest claim collapsed because command shape silently changed the
+  the lane has and comes before any further reduction.
-  binary; no further reduction should be trusted until each row names
+- **D0b — re-run the §4 matrix with captured provenance**, at `main`,
-  the executable it ran.
+  recording the artifact hashes actually executed **at run time**.
+  Revision 2's strongest claim collapsed because command shape silently
+  changed the binary; no further reduction should be trusted until each
+  row names the executable it ran.
 - **D1 — key on the PID this test records.** The test already owns
   `launcher.id()`. Capture around its own `kill`, not by scanning for
   age or command line.
@@ -246,10 +289,13 @@ Written now so the fix cannot quietly become "make the test pass".
   unobtainable before this lane is approved, gated and merged, and
   revision 1 stated an impossible precondition. Post-merge
   confirmation on `main` is a follow-up, not a gate on the fix.
-- **A3.** The R9 paradox is explained, or explicitly recorded as
+- **A3.** There is no established "R9 paradox" to explain — R9 ran
-  unexplained. A fix that greens the sweep without accounting for why
+  different binaries, so the comparison it appeared to make was never
-  every subset passed leaves a gap, and the gap is stated rather than
+  made. What A3 requires instead: **D0 recreates the subset/full
-  left for the next reader.
+  comparison under captured provenance**, and whatever it then shows is
+  either explained by the fix or explicitly recorded as unexplained. A
+  fix that greens the sweep without that comparison having been made
+  properly leaves the gap stated, not hidden.
 - **A4.** No deadline raised, no test skipped, retried, or serialised
   to obtain green.
 - **A5.** **Conditional on D4.** If bet 1 holds, this is unconditional:
@@ -292,9 +338,13 @@ when revision 2 was reviewed, and both are closed by this revision:
   processes "should both die at once" and then withdrew that same claim
   further down. The assertion is removed; only the withdrawal and its
   reasoning remain.
-- **`panel-mapping-generation` @ `16cf3a2`** still carried "119
+- **`panel-mapping-generation`** carried "119 binaries green, one
-  binaries green, one red", the ≥8 s arithmetic, the "default action"
+  red", the ≥8 s arithmetic, the "default action" claim and the ">6 s
-  claim and the ">6 s selector". Pushing `16cf3a2` made the *retraction*
+  selector"; `779a6bd` corrected those. **It still carried more**,
-  portable but not the *correction*. That ledger is corrected on its own
+  found on re-review: `--workspace` unification "refuted", R9 running
-  branch and pushed, so the held lane no longer transports falsified
+  the "same binaries", later packages that "cannot be implicated", and
-  claims.
+  a cause "cumulative across the preceding 37 binaries". Revision 3's
+  claim here that the held lane no longer transports falsified claims
+  was **premature**; those are corrected now, and this section should
+  be read as a checklist that has been re-verified rather than an
+  assurance.

docs/probe-sigint-evidence.md

@@ -11,7 +11,10 @@ identified here by SHA-256 prefix and byte count.
 These runs were made **before** this manifest existed, so their
 provenance is **reconstructed, not captured**. Specifically:
 
-- **Commands** are exact — they are the literal invocations issued.
+- **Commands** are exact and complete argv. Revision 3 abbreviated
+  R7–R9 as "`--test` ×N (targets 6–37)" and F5 as "`--acceptance` ×6",
+  which are descriptions, not reconstructable invocations. They are
+  written out in full below.
 - **Worktree** is exact.
 - **HEAD** is given as a range where the run cannot be pinned to one
   commit, and marked `~`. It is never guessed at single-commit
@@ -22,20 +25,31 @@ provenance is **reconstructed, not captured**. Specifically:
 **D0 (below) exists because of this.** No conclusion in §4 should rest
 on a `UNKNOWN`-cleanliness row once D0 has replaced it.
 
-## The artifact-identity column, and why it exists
+## Artifact identity — suffix is NOT byte identity
 
-Reduction and sweep runs did **not** always execute the same compiled
+Two distinct things were conflated in revision 3 and are separated here.
-test executables. Cargo's target selection changes the fingerprint, so
-`--test a --test b` and `--workspace` can produce byte-different
-binaries for the same source. Verified:
 
-| family | `gpu_initial_target_acceptance` | `gpu_invocation_acceptance` |
+**Cargo suffix** is recorded in each log and is therefore *known* per
+run. **Byte identity** is not: target directories have been overwritten
+many times since, so a hash computed today is the hash of whatever
+occupies that path now, not of what a given run executed.
+
+That the two differ is demonstrated, not assumed. F1 ran in the `main`
+worktree (`pmacs-fdccc423`) and executed suffixes `-5d9105cb7047aab8`
+and `-d4dae4f01bcdef62` — **the same suffixes** as the panel-worktree
+sweeps — yet the bytes at those paths differ by worktree:
+
+| worktree | `gpu_initial_target…-5d9105cb` | `gpu_invocation…-d4dae4f0` |
 |---|---|---|
-| reduction (R7–R9) | `-91f51d0b5303ff9f`, sha `36912fa25a72ffc7` | `-6b4b8223dea45247`, sha `858d71486d0b66f0` |
+| `pmacs-fdccc423` (main) | `e057803988c34cf7` | `00f06aeb089ce38d` |
-| workspace (R10, F1–F5) | `-5d9105cb7047aab8`, sha `1b3cc86cbb8d6092` | `-d4dae4f01bcdef62`, sha `ede0c07dd9abb456` |
+| `pmacs-mapping-gen-…` (§5b) | `1b3cc86cbb8d6092` | `ede0c07dd9abb456` |
 
-They are byte-different. Any claim of the form "the same binaries pass
+Same suffix, different source head, different bytes. So **"workspace
-as a subset" is therefore **unsupported by these runs**.
+artifact family" was not an identity class** and is withdrawn as a
+grouping. Each run below records the suffix its log shows, and byte
+identity as `UNKNOWN` unless contemporaneously captured — which, for
+every pre-manifest run, it was not. R1 and R2 have no preserved log at
+all and so cannot claim even a suffix.
 
 ## Runs
 
@@ -53,25 +67,58 @@ except `WT=main`, which uses `…/pmacs-fdccc423`.
 | R4 | `test --features crdt --lib --test gpu_invocation_acceptance --no-fail-fast` | mg | ~`724b785`–`5174f73` | UNKNOWN | reduction | green, 2145 + 15 | `89050c702de22d57` 158812 |
 | R5 | `test --features crdt --no-fail-fast --test gate_script_acceptance --test gpu_invocation_acceptance` | mg | ~`5174f73`–`b72843a` | UNKNOWN | reduction | green | `31b3e5249b475479` 3706 |
 | R6 | `test --features crdt --no-fail-fast --test gpu_font_acceptance --test gpu_initial_target_acceptance --test gpu_invocation_acceptance` | mg | ~`5174f73`–`b72843a` | UNKNOWN | reduction | green, 11+15+15 | `332693a39c73731a` 4569 |
-| R7 | `test --features crdt --no-fail-fast --lib --bins` + `--test` ×14 (targets 6–19) + `--test gpu_invocation_acceptance` | mg | ~`b72843a` | UNKNOWN | reduction | green | `9e1ebc59ed9f0dd4` 187531 |
+| R7 | `test --features crdt --no-fail-fast --lib --bins --test acceptance --test ambient_isolation_acceptance --test auto_indent_acceptance --test auto_indent_crdt_acceptance --test auto_pair_acceptance --test auto_pair_crdt_acceptance --test autosave_acceptance --test bottom_panel_stage1_acceptance --test bottom_panel_stage2a_acceptance --test bottom_panel_stage2b_daemon_acceptance --test bottom_panel_stage2b_gpu_acceptance --test bottom_panel_stage2b_protocol_acceptance --test comment_toggle_acceptance --test compile_mode_acceptance --test gpu_invocation_acceptance` | mg | ~`b72843a` | UNKNOWN | `-91f51d0b` / `-6b4b8223`; bytes UNKNOWN | green | `9e1ebc59ed9f0dd4` 187531 |
-| R8 | `test --features crdt --no-fail-fast --test` ×18 (targets 20–37) + `--test gpu_invocation_acceptance` | mg | ~`b72843a` | UNKNOWN | reduction | green | `8b26ebfcf5f871b4` 28677 |
+| R8 | `test --features crdt --no-fail-fast --test compile_mode_crdt_acceptance --test completion_popup_acceptance --test config_registry_acceptance --test cua_region_acceptance --test desktop_acceptance --test destination_capture_acceptance --test dired_acceptance --test discovery_acceptance --test discovery_stage2_acceptance --test editops_acceptance --test find_file_acceptance --test folding_acceptance --test folding_stage2_acceptance --test full_grid_resync_acceptance --test gate_script_acceptance --test git_status_stage1_acceptance --test gpu_font_acceptance --test gpu_initial_target_acceptance --test gpu_invocation_acceptance` | mg | ~`b72843a` | UNKNOWN | suffixes per log; bytes UNKNOWN | green | `8b26ebfcf5f871b4` 28677 |
-| R9 | `test --features crdt --no-fail-fast --lib --bins` + `--test` ×32 (targets 6–37) + `--test gpu_invocation_acceptance` | mg | ~`b72843a` | UNKNOWN | **reduction** | green | `b31d98ee2f427eca` 214566 |
+| R9 | R7's argv with R8's eighteen `--test` names spliced in before `--test gpu_invocation_acceptance` — i.e. `test --features crdt --no-fail-fast --lib --bins` then `--test` for each of targets 6–37 in sweep order, then `--test gpu_invocation_acceptance`. Full list = R7's ∪ R8's, deduplicated, order preserved. | mg | ~`b72843a` | UNKNOWN | **`-91f51d0b` / `-6b4b8223`** (log `:3066`); bytes UNKNOWN | green | `b31d98ee2f427eca` 214566 |
-| R10 | `test --workspace --features crdt --no-fail-fast --test gpu_initial_target_acceptance --test gpu_invocation_acceptance -- --skip basedpyright` | mg | ~`b72843a` | UNKNOWN | **workspace** | green | `81b48fd7a0e261dc` 3553 |
+| R10 | `test --workspace --features crdt --no-fail-fast --test gpu_initial_target_acceptance --test gpu_invocation_acceptance -- --skip basedpyright` | mg | ~`b72843a` | UNKNOWN | **`-5d9105cb`** (log `:3`); bytes UNKNOWN | green | `81b48fd7a0e261dc` 3553 |
-| F1 | `build --workspace --no-default-features --features luajit,crdt && test --workspace --features crdt --no-fail-fast -- --skip basedpyright` | **main** | `72da24a` | clean (verified `git status --porcelain` empty) | workspace | **red** | `10b55b8ba8741125` 334446 |
+| F1 | `build --workspace --no-default-features --features luajit,crdt && test --workspace --features crdt --no-fail-fast -- --skip basedpyright` | **main** | `72da24a` | clean (verified `git status --porcelain` empty) | `-5d9105cb` / `-d4dae4f0`; bytes at those paths **today** `e0578039…` / `00f06aeb…`, i.e. NOT the panel worktree's | **red** | `10b55b8ba8741125` 334446 |
-| F2 | `test --workspace --features crdt --no-fail-fast -- --skip basedpyright` | mg | ~`b72843a` | UNKNOWN | workspace | **red** | `474f88f0dad581fe` 338555 |
+| F2 | `test --workspace --features crdt --no-fail-fast -- --skip basedpyright` | mg | ~`b72843a` | UNKNOWN | `-5d9105cb` / `-d4dae4f0`; bytes UNKNOWN | **red** | `474f88f0dad581fe` 338555 |
-| F3 | same as F2, with resource sampler | mg | ~`b72843a` | UNKNOWN | workspace | **red** | `7b8519e7300e8bb3` 338555 |
+| F3 | same argv as F2, with a resource sampler running | mg | ~`b72843a` | UNKNOWN | as F2; bytes UNKNOWN | **red** | `7b8519e7300e8bb3` 338555 |
-| F4 | same as F2, with process sampler | mg | ~`b72843a` | UNKNOWN | workspace | **red** | `5ccdefc5d89eece3` 338555 |
+| F4 | same argv as F2, with a process-table sampler running | mg | ~`b72843a` | UNKNOWN | as F2; bytes UNKNOWN | **red** | `5ccdefc5d89eece3` 338555 |
-| F5 | gate stage 15 of `./scripts/gate --protocol --acceptance ×6` | mg | `5174f73` + docs | UNKNOWN | workspace | **red** | gate log `20260817T172537Z-2375685/15-sweep-crdt.log` |
+| F5 | stage 15 of `./scripts/gate --protocol --acceptance bottom_panel_stage1_acceptance --acceptance bottom_panel_stage2a_acceptance --acceptance bottom_panel_stage2b_daemon_acceptance --acceptance bottom_panel_stage2b_gpu_acceptance --acceptance bottom_panel_stage2b_protocol_acceptance --acceptance gui_stage1a_wire_acceptance` | mg | `5174f73` + uncommitted docs | UNKNOWN | suffixes per log; bytes UNKNOWN | **red** (3 bins: both ctrl_c copies + `m6_1_pty_mode_lifecycle`) | `20260817T172537Z-2375685/15-sweep-crdt.log`, sha `e5bdc911e366` |
+| F6 | stage 9 of `./scripts/gate --protocol` | mg | `5174f73` | UNKNOWN | suffixes per log; bytes UNKNOWN | **red** (2 bins, both ctrl_c copies) | `20260816T063330Z-1977433/09-sweep-crdt.log`, sha `7a75d999ac4f` |
+| F7 | stage 9 of `./scripts/gate --protocol` | mg | `5174f73` | UNKNOWN | suffixes per log; bytes UNKNOWN | **red** (2 bins, both ctrl_c copies) | `20260816T064549Z-2144707/09-sweep-crdt.log`, sha `9d3c6ad1bfc9` |
 
 Supporting, not a reduction: `9b8a01076b44bb7c` 98838
 (`proc-sample.log`) is the process-table sampler output behind the
 retracted "mechanism located" claim.
 
+**The red count is 7, not 5.** Revision 3 said "F1–F5, red 5/5" while
+the framing separately cited gate `…-2144707`, a *different* physical
+run the manifest never listed. Both exist, both are red, and there is a
+third gate run too. F1–F7 above enumerate all seven, each with its own
+log digest. F5 also has an extra failing binary
+(`m6_1_pty_mode_lifecycle_started_then_exited`) that F6/F7 do not.
+
 **R2 and R6 are distinct runs.** Revision 2's §4 cited `gpu3.log` for
 both; that log is R6's three-suite run only, and R2's log was never
 preserved. R1 likewise has no log. Both are marked accordingly rather
 than backfilled.
 
+## The onset is datable — and this supersedes the reduction matrix
+
+`sweep-crdt` has run 17 times in this target directory's gate logs. The
+`ctrl_c` failure appears in **exactly the last three**, and the test
+**passed inside `sweep-crdt`** — both copies, `... ok` — in the runs
+before them.
+
+| date | gate run | sweep-crdt | ctrl_c |
+|---|---|---|---|
+| 08-14 → 08-15 19:57 | 14 runs | 11 green; 3 red on *other* tests | **passes** where the stage ran it |
+| 08-16 06:33 | `…-1977433` | red, 2 bins | **fails, both copies** |
+| 08-16 06:45 | `…-2144707` | red, 2 bins | **fails, both copies** |
+| 08-17 17:25 | `…-2375685` | red, 3 bins | **fails, both copies** |
+
+The three earlier red sweeps failed on unrelated tests — protocol and
+version rows on 08-15 09:55, and `composition_overhead_under_ten_percent`
+plus a v21/v20 row on 08-15 18:37. **None involved `ctrl_c`.**
+
+So the failure is **not long-standing**. Last green containing it:
+`20260815T185708Z`. First red: `20260816T063330Z`. Something changed in
+that window, on a machine that was not rebooted (uptime spans it).
+**Bisecting that boundary is a sharper lead than any reduction**, and
+D0 is amended to do it first.
+
 ## D0 — re-run the matrix with captured provenance
 
 Before any §4 row is relied on for a conclusion, re-run the reductions
@@ -82,6 +129,11 @@ log digest. Two constraints learned the hard way:
 
 - run them **at `main`**, not on a feature branch — R1–R10 ran in the
   `panel-mapping-generation` worktree, which carries §5b changes;
-- record the **artifact hash per run**, since command shape changes it,
+- record the **artifact hash per run at run time**, since command shape
-  which is the whole reason R9's result did not mean what it appeared
+  changes it — the reason R9's result did not mean what it appeared to
-  to mean.
+  mean — and since a hash computed later reflects only what occupies
+  that path now;
+- **first, bisect the 08-15 19:57 → 08-16 06:33 onset window.** A test
+  that passed in this stage fourteen times and then failed three times
+  in a row has a change behind it, and finding that change is worth
+  more than any further reduction.