Promotes the two throwaway sanitizer harnesses used to diagnose the
2026-08-16 soul crash into engram/test/ so the bug cannot silently regress.
The harness has two halves and the PAIR is the point — it is what localises
the defect to concurrency rather than to HNSW logic:
single 3000 clustered vectors, one thread, ASan+UBSan. The CONTROL.
Must always be clean. During diagnosis this cleared all 13,820
real dim-768 vectors from the live store, which DISPROVED an
inspection-derived hypothesis about an out-of-bounds
reverse-link write at engram_vindex.c:340.
concurrent writer + reader on one shared index, TSan. Currently reports a
race at engram_vindex.c:195 (visited_reset) reached from both
vindex_search and vindex_insert, because VIndex still owns its
visited[]/visit_epoch scratch — so even two concurrent READS
corrupt each other's traversal.
Verified: half 1 passes, half 2 reproduces the race.
Gated on EXPECT_RACE, default 1, so the concurrent half documents the known
defect without failing the suite today. When the visited set moves to a
per-query checkout pool (hnswlib VisitedListPool style — NOT thread_local,
since http_worker is a thread per connection and a __thread buffer would leak
~55KB per connection), flip EXPECT_RACE=0 and it becomes a real gate.
Lands feat/reframe-region-setop (PR #109: native set-based reframe_region,
decorator-as-seam @route port, teacher-summon, and the M8.1 activate-latency
work — lazy-memoized cosq via eg_cosq_at + engram_vindex HNSW-accelerated
seed discovery + vindex_harvest_from_store/vindex_bench oracle) onto dev's
actual current HEAD, plus engram-tiered-storage's still-unique test suite.
RECONCILING #109 WITH engram-tiered-storage (M4-M10 HNSW/geometry/reason/
verify work): not a two-way merge. engram_vindex.c's HNSW core (search_layer/
select_neighbors/prune_links/insert) is BYTE-IDENTICAL between the two
branches; #109's copy is a strict superset (adds vindex_harvest_from_store,
used by vindex_bench.c's brute-force-vs-HNSW oracle). engram_reason.c and
engram_verify.c are also byte-identical. #109's own branch point already
carried engram-tiered-storage's M4-M10 lineage forward, so there was nothing
left to merge into #109 for those files. The one thing engram-tiered-storage
had that #109's tree dropped: its full test suite (test_vindex.c,
test_geometry.c, test_reason.c, test_verify.c, test_m7_traversal.c, the
interoception P0-P5 tests, bufpool/compaction tests, and their run_*.sh
harnesses) — ported over here unchanged.
WHY THIS NEEDED HAND RECONCILIATION, NOT A MECHANICAL MERGE: #109's branch
forked from dev on 2026-08-14 15:40 (before restructure-adjacent history
diverged the file's merge-base for `git merge` — it presented as an add/add
conflict). A straight two-dot diff (dev tip -> PR tip) applied cleanly, but
it silently reverted THREE dev fixes landed on 2026-08-14/15, after the
branch point, that the PR's diff had no way to know about:
1. qgate rescale (2026-08-14 self-review): PR's lazy eg_cosq_at rewrite of
the query-aware propagation gate dropped the shift-and-floor rescale
about ENGRAM_EMBED_S0 (measured: unrelated-pair median 0.562->raw gate
0.67, i.e. "a small tax, not a gate"). Restored the rescale, wrapped
around the lazy accessor -- the PR's actual improvement (WHEN cosq[oi]
is computed) is orthogonal to WHAT it gates on and both are kept.
2. Eviction cause decomposition (2026-08-14 self-review): dev decomposes
wm_evicted into evict_floor/evict_cap/evict_bll so WM churn is
diagnosable (identity: evicted == floor+cap+bll+dup_wm+dup_wm_global).
PR's tree predates this and dropped all three counters + their JSON
stats fields. Restored declarations, all 4 direct increment sites, the
eg_wm_carry_over bll increment, and the act-stats JSON fields --
alongside (not instead of) the PR's own P4 afferent / API-reshape
counters already in that same struct/JSON.
3. Hebbian link-formation selection (2026-08-15 self-review, TODAY): dev
selects the STRONGEST qualifying candidate for consolidation each call;
PR's tree predates this and reverted to hash-slot order (arbitrary wrt
association strength) for edge formation -- the one path that writes
PERMANENT structure. Restored the strongest-candidate while-loop,
keeping the PR's own genuine improvement at that site
(engram_adj_on_edge_added incremental-index append instead of a bare
adj_dirty=1 full-rebuild flag).
engram/src/server.el's 3-way conflicts (autoconnect_on/ise_offgraph_on env
flags, /api/nodes connected-count in responses) were pure additive: dev's
side was empty, PR's side added the feature. Took PR's side whole.
VERIFIED (nsbx sandbox only, live :8742/:7770 never touched):
- cc -std=c11 -O2, clean link against the real engram/src/server.el via
elc, zero errors.
- vindex_bench (built standalone, read-only harvest) against the real
production store clone (13,671 embedded nodes, 768-dim nomic-embed-text):
recall@10 = 1.0000 at ef 64/128/200; HNSW search 0.28-0.79ms/query vs
2.03ms/query brute-force oracle (2.6x-7.2x). HNSW build itself: 46.5s
for the full 13,671-node set -- see the flagged risk below.
- Booted the reconciled binary in an isolated nsbx sandbox (:8905, cloned
snapshot of the live store, 13,424 nodes / 37,656 edges) and called
/api/activate for real: first call after boot 41.5s (pays the one-time
HNSW build inline -- matches the standalone bench), second/third calls
356ms/605ms, no crash, correct results, act-stats JSON (including the
restored evict_floor/cap/bll fields) reads correctly.
KNOWN RISK TO FLAG BEFORE ANY LIVE CUTOVER (not fixed here; out of scope for
this dev-only land per instructions not to touch :8742/:7770): eg_vindex_sync
builds the HNSW index synchronously, inline, on the first engram_activate()
call after every process start (or index invalidation). On the real node
count that is a ~46s blocking stall on a single-threaded server -- the first
request after every restart (or its concurrent siblings) waits the full
build. Recommend a background/incremental build (or a bounded per-call build
budget) before this ever reaches the live daemon. See PR description / final
report for the fuller writeup.
Flag-on checkpoint now full-walks the resident graph: store_put_node (WM weight,
activation_count, last_activated, wm_anchor) + store_put_edge (hebb, last_fired)
for every node/edge, then engram_checkpoint. Uses store_put_edge (idempotent
upsert) not store_hebb_batch, because activation FORMS new hebbian-associate edges
that bypass the create hook and delta-only hebb_batch can't create them. Store-on
boot now applies the same WM-halving + floor + cap transforms as engram_load.
This is the hebb-survives-restart fix. Gate: reboot from neuron.egm with
snapshot.json deleted -> edge hebb + activation_count survive unchanged, WM weight
survives with identical boot transform; negative control proves persist is
load-bearing (hebb->0 without it). M1 33/33 + M2 36/36 + M3 parity PASS, ASan/UBSan
clean, flag-off untouched. Engine unchanged (boundary held).
Caller-side shim in el_runtime.c maps EngramNode/Edge <-> StoreNode/Edge; engine
keeps zero soul deps (libengram boundary, design §10). Flag off = today's JSON
path byte-for-byte (proven: no neuron.egm created, graph identical). Flag on =
engram_open (import snapshot.json once into neuron.egm, else WAL-replay) +
resident load; node/edge create + forget dual-write via guarded hooks. Files
renamed engram.store->neuron.egm, engram.wal->neuron.wal.
Gate: M3 parity PASS (graph on==off byte-exact modulo ordering; snapshot round-trip;
reboot-from-egm with snapshot.json deleted; activation set+sequence identical;
ASan/UBSan clean). M1 33/33 + M2 36/36 green post-rename.
Known gap (pre-flip): in-place hebb/WM/activation_count updates during activation
are not yet persisted to the store (create/connect/forget are). Must close before
live flip so learned edges survive restart.
Write-back no-steal buffer pool makes the fsync'd WAL load-bearing (M1 was
write-through). Logical WAL with record-granularity page-LSN redo idempotency.
Checkpoint = flush dirty pages, fsync store, advance last_checkpoint_lsn,
reclaim WAL prefix. One-time snapshot.json import only when store absent;
JSON never read as the ongoing store thereafter.
Gates: 33/33 M1 (no regression) + 36/36 M2 — replay parity, torn-tail fuzz
(every byte offset), checkpoint-crash at all 5 phases, torn-page+WAL redo,
legacy-import parity, hebb-survives-crash.
Establish lang/runtime/ as the ONE canonical el runtime (from the active
runtime that carries hebb/emb persistence + the new WAL); repoint the el CI
publish, engram build, elb default, and in-repo build scripts to it; delete
the el-compiler/runtime + lang/releases/ forks; add scripts/check-single-runtime.sh
drift guard.
Fixes a live prod bug: the el CI published el-runtime-c/-h from the LAGGING
el-compiler fork (0 hebb refs), so the shipped soul never persisted Hebbian
edge weights — learned co-activation was wiped on every restart. Publishing
from canonical ships the stranded 'learning that cannot outlive the process'
fix.
WAL storage engine + integrity fixes (DELETE->tombstone + store-layer
protection, safe data-dir default) ride in behind ENGRAM_WAL (default off =
byte-identical to today). Verified: engram elb per-module build clean, WAL
gate 66/66, native smoke ok, drift-guard green.
bigmerge
will.anderson