The 0c mechanism probe was run on this host before any structural work, because
one unverified assumption could have invalidated the whole approach: whether a
hand-created `adapter` node is visible to pipewire-pulse under the name the
capture path depends on. It is. Five gates green, including the two that
mattered — `<node.name>.monitor` is exposed as a Pulse source, and SIGKILL of
the owning connection removes both Pulse-visible names with zero graph residue.
No null-sink module is involved at any point. Every O1 stop condition for 0c is
retired, and the default sink never moved, so the probe is safe on a live
desktop.
The probe also settled the native-sink scope question: it applies to every mode
that owns a capture sink, not only `DesktopExcluding`. That makes the `--repair`
rework load-bearing rather than defensive — repair derives dead PIDs only from
`module-null-sink` entries, so once the sink is native its loopbacks become
undiscoverable orphans.
§10 gains rounds 14 and 15: the 0b matrix drops to four mutations because the
best-effort wake arm is unreachable by construction (the loop owns a sender, and
the biased select would win anyway), and teardown is hoisted to one unconditional
post-loop site instead of being duplicated across one live arm and one dead one.
Round 15 records the two blocking implementation-review findings and the vacuous
gate of my own that the review's test-double critique exposed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Design v3.7 §6.1.1 gains the round-13 box (the rule, the ordering that is
load-bearing in both directions, and why bridging deliberately still uses the
full union); the phase-5 results file records the close with the measurement
the deferral was waiting for; the impl plan's phase-6 gate note drops F11-1.
pixelpass c78eb2d is the implementation.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The §5.1 dry-run audit gate passes. All 13 rows completed with a non-empty
eligible half in every one, and O5 is re-measured on the fixed graph: worst
recompute 67 µs across every run, 10 µs mean under deliberate churn, busy
fraction 0.0006, readiness 1-2 ms with 18 binds against a 2000 ms budget.
Round 10's finding, and it is the third of exactly the same shape: the
pipewire-pulse PID derivation required a SINGLE repeated pipewire.sec.pid.
WirePlumber repeats one too (two Clients, both sec_pid 1747), so the derivation
returned None permanently on a stock desktop, key 4's suppression never fired,
and every Pulse-emulated node fused into one owner. Row 1's CLEAN control
forwarder and Firefox were both excluded. Fixed in pixelpass 91c4ded by deleting
the heuristic: probe every distinct sec_pid and let /proc/<pid>/comm decide.
Three measured rounds now, all at the observation boundary, none in the
architecture -- and all three were fail-closed and silent, caught only because
§5.1 requires asserting what must remain ELIGIBLE. An exclusion-only checklist
would have passed every one of these builds.
Rows 4-6 are closed through peerspeak's REAL tagging sites (call, mpv, notify,
plus clip) with a hand-launched mpv staying eligible, so the cross-repo contract
is proven end to end on live nodes. Row 10 covers the full sticky lifecycle
including retirement; row 11 is provably non-vacuous (the recycled
node.link-group came back byte-identical and did not inherit taint).
Recorded and NOT claimed as passes: substitutions in rows 8, 9 and 13, and two
reporting-only findings (the audit's sticky flag is uninformative; a bridge's
named key is lost when a leg reappears under a new serial).
Phase 6 remains blocked by F11-1, phases 0b/0c/0d and the Stereo Mix design
call -- this file removes one gate, not all of them.
Phase 3r landed §6.7 and the phase-5 audit was re-run against it immediately.
It found a second measured defect within minutes: a real hardware sink
carrying `unresolved-ancestry` permanently, from one link observed while its
output node was still unbound during enumeration. Round 8 made that
systematic rather than rare, because every node is now withheld until its
bind resolves.
New §6.8: sticky taint is a claim about history, and uncertainty is not
history. Retiring by reason code would not be enough — an unresolved node
propagates `TaintedUpstream`, which is indistinguishable from real
contamination once recorded — so the split is by provenance: the engine runs
its fixpoint twice, and only the evidence-only pass may feed sticky state.
Decisions are unchanged and still fail closed.
Also recorded in §6.8, both from Codex's round-9 review and both pre-existing:
hardware playback-to-capture paths ("Stereo Mix") defeat the `session_device`
classifier in a way the driver denylist cannot detect — a real echo path
needing a design call — and the 2 s readiness budget has no calibration
argument beyond one measurement on one idle desktop.
Impl plan: phase 3r marked built and merged with its gate results, including
the extra Device-side live gate and why row 1 alone could not cover it.
The phase-5 dry-run gate failed on its first live run: the engine built to
v3.4 could not see its own primary taint root (echo, AEC off) while excluding
every stream on the machine (silence). One cause — the PipeWire registry
`global` event carries only a filtered subset of an object's properties, and
eight the design depends on are never announced.
Design doc (v3.4 → v3.5):
- NEW §6.7 — the observation boundary. The global is an index, not a source of
truth: bind every Node and Device, `info` props are the sole source, live
prop tracking, one readiness obligation per unbound node, fail closed.
Four user design calls recorded.
- §5.1 — a second, registry-visible tag carrier (`node.name` prefix) alongside
`peerspeak.owned`, so the primary root does not rest on one mechanism.
- §6.4 — node/device props are not an optimisation to skip, they are
unavailable from the global; the round-6 Link lesson was right and applied
to exactly one object type.
- §6.1.0, §6.1.4 — the two corrections the impl plan owed v3.5: a
time-dependent "hazard is LIVE" claim, and an unreachable nominated test
case (twice over).
- §9.1 measured facts, §12 rig discipline (pw-dump binds; the registry does
not), §14 readiness.
Impl plan:
- NEW phase 3r with a four-part exit gate, the first the direct inverse of the
finding. Ports deliberately not bound in v1, with a revisit trigger.
- Phase 1 pins the second carrier literal as a cross-repo contract.
- Phase 5 marked GATE FAILED; matrix and O5 re-run after 3r and 1.
- Risk register: the over-exclusion row fired and worked; new row for the
observation boundary class.
Architecture is unchanged and vindicated: fed correct properties, the engine
decided correctly in every fixture. The §5.1 exact-partition requirement is
what caught this — every exclusion was defensible and the eligible half was
empty.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Turns the converged v3.4 design into ordered phases with falsifiable exit
gates. Three adversarial review rounds with Codex (gpt-5.6-sol, xhigh);
findings adjudicated rather than accepted wholesale, with reachability
verified against source on both sides.
Structural decisions:
- Phase 0d closes BOTH unsafe paths into the capture (source string and
capture-sink inputs) before any machinery that could take them exists.
- Phase 5 dry-run audit mode is a hard gate: the taint engine runs against
the live graph, creating no links, asserting exact eligible/excluded
partitions with reason codes.
- Link manager is deliberately last among the pixelpass components.
Two measured corrections owed back to v3.4 (plan §11): §6.1.0's "hazard is
LIVE right now" has already flipped and must not be gated on, and §6.1.4
nominates an unreachable test case (as did my first replacement for it).
Design approval only. No code, nothing approved for merge.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
molluskandClaude Opus 5