Timeline

The other three on-disk formats defined in terms of this checksum: the cache image self-checksum, the bisect session trailer, the undo journal trailer. Same swap, same values. check-in: 55d6e7c7bb user: dmestas tags: logstore-index

The four frame checksums plus the file header. The open-time scan CRCs every payload byte, so this is ~93% of a cold open: 416 MB goes 1.22s to 292ms. No format change — the values are identical by construction. check-in: dd71dd3006 user: dmestas tags: logstore-index

Bit-identical to std.hash.Crc32, which every on-disk checksum in the store is already defined in terms of. std's is byte-at-a-time over one table (~350 MB/s here); this folds eight bytes per step. Nothing uses it yet. check-in: aef8f539b5 user: dmestas tags: logstore-index

Emission is off by default and turning it on is an explicit act that must name the partition parameter: there is no fallback value, enabling without one is refused, and a pinned value outside the supported range emits flat manifests and says so rather than substituting a parameter of its own. Turning it off returns the next commit to flat. The analysis pass reports what the parameter would cost over a name set; it pins nothing.

A server whose setting is off now sends the avoid-submanifests pragma, which the receiving side already latched. It leads the pragma run in both the ordinary and the clone reply, so six tests that read a reply's first card were updated to account for it; each still asserts the same content it did before, behind the new card. Fossil 2.28 tolerates the pragma and the interoperability suite is unchanged.

The parameter is repository-local. The specification requires it to propagate to clones, since sharing by content address holds only while every writer partitions identically; that shortfall is recorded rather than implied away. check-in: 92a40960d1 user: dmestas tags: sub-manifest

An absent S reference now phantomizes like any other missing reference, its dependent is deferred and retried when the artifact arrives, and the sweep excludes sub-manifests so it still terminates. Phantoms survive a restart through a rebuild-on-open invariant resting on a durable seen-submanifest setting rather than on records the log never wrote. The transfer gate decides by artifact shape on all three send paths, so a leaf is refused wherever a tree manifest is, and the memo returns its own copy rather than a view into pages the store may free.

The gate remembers what it withheld from a peer, which is what lets an exchange with a peer that refuses sub-manifests terminate at all. That record is now cleared only when the peer's announced version actually changes: a peer that re-announces the same version in every reply was clearing it every round, so the same artifacts were offered and refused forever.

One requirement is not implemented: a server whose setting is off must send the avoid-submanifests pragma, and emitting it changes the card sequence every clone-reply test walks. That is a protocol-shape change worth its own review rather than a rider here; the pragma is parsed and latched on receipt already. check-in: 8446adcd98 user: dmestas tags: sub-manifest

Sub-manifests have no reference implementation to check against, so the corpus is the oracle and had to be built rather than assumed. Adds the eleven vectors Appendix A.5 requires that were missing, among them the three-level tree whose absence is why the step-5 cursor contradiction survived into an implementation: no published artifact carried an interior node, so nothing exercised that path.

Every authored vector is generated by the implementation and then rechecked along a path that shares no code with it, and each derived name is compared against the constant the test pins, so no hash in the corpus is hand-written. Two fuzz targets cover S-card classification and the tree walk.

One A.5 bullet is not satisfiable as written: the re-tune vector asks for two parameters over the A.1 name list that yield trees sharing no sub-manifest, but that list's single qualifying boundary falls in the same place for the first three values and is suppressed above them. No vector was invented for it; an erratum is drafted and a test pins the finding so it stays visible. check-in: 72bba34ada user: dmestas tags: sub-manifest

Regenerated from the RFC suite after the erratum submanifests-00-s5.1-step5-cursor-advance was applied. Step 5 of the tree walk now advances the referencing frame's cursor before pushing the interior frame; as published it omitted that, so returning from an interior descent re-read the same S card and failed the strictly-greater-than-LAST check, leaving every tree with an interior node unwalkable. The walk already implements the corrected reading. Also picks up an MD5 citation and reflowing in unrelated paragraphs. check-in: f2973c41c3 user: dmestas tags: sub-manifest

The merge fires when the two groups together hold at most MAX, and no test separates that from a strict comparison. Reaching the distinguishing case needs a natural boundary at exactly MAX minus the tail, which hash-driven boundaries do not produce in generated name sets; a search over two parameter values and nine hundred starts found no instance. Pinning it would mean choosing filenames by their leading zero bits rather than generating them. The note records the reasoning at the site so the gap is visible to the next reader. check-in: 9897845809 user: dmestas tags: sub-manifest

The S hash is validated case-insensitively and kept raw, so a parsed card carries whatever spelling it was given. The writer asserted the narrower lower-case spelling, so re-emitting a card the parser had just accepted tripped the assertion. It now asserts the parser's own predicate.

Reachable only once something emits, which nothing does yet; found by round-tripping an upper-case hash through create. check-in: 6e64c8976c user: dmestas tags: sub-manifest

Implements draft-fossil-submanifests-00 section 6: zbits over the decoded filename, the group scan with its MIN/MAX member bounds, and the final-group merge. One scan serves height 0 and every height above it, so the merge applies uniformly rather than through two code paths that can drift; appendix A.4 is the vector that fails when they do.

Construction emits filenames through a minimal encoder scoped to its own output only. Existing emission keeps the escaping it has always used, so no check-in already written changes its bytes. R cards are emitted for tree manifests alone.

Nothing emits yet: the construction is wired behind a disabled flag, leaves stored before the nodes that reference them. The gate that turns it on is a later change. Tests pin k = 3, the value the appendix vectors use, and cover byte-identity against A.2, A.3 and A.4, determinism across repeated builds, and a constructed tree walking back to the entries it partitioned. check-in: 9d7992613f user: dmestas tags: sub-manifest

Implements draft-fossil-submanifests-00 sections 5.1 through 5.6: a stack walk over S runs with the section's depth bound, cycle check, strict ascent and first-filename identity, resolving sub-manifests through the existing baseline resolver. A tree that fails any check fails whole, so a partial enumeration is never presented as a file set.

The walk sits in a pre-pass at the facade, leaving enumerate, lookup and their call sites untouched as section 9.3 requires. R-card verification runs over the walked enumeration.

Step 5's cursor advance follows the erratum submanifests-00-s5.1-step5-cursor-advance: as published, step 5 omitted it, and no tree carrying an interior node could be walked. check-in: d1f955aaf3 user: dmestas tags: sub-manifest

Adds S as the twenty-second card letter and SUBMANIFEST as the ninth artifact type, per draft-fossil-submanifests-00 sections 3 and 4. Type determination reassigns after the card scan rather than during it, so no type is committed while cards are still being read (section 9.1). Reading and classification only: no tree walk, no emission.

The draft's seven appendix vectors ship alongside, each named by the SHA3-256 the draft states and checked by a test that recomputes it. check-in: 9b8bad477a user: dmestas tags: sub-manifest

A serving release over 0.1.2. Where 0.1.2 made a large repository cloneable, 0.1.3 makes serving one fast and lean.

A server against a large repository comes up immediately: the listener opens before the repository is read, so a client queues in the accept backlog while the server primes rather than being refused during a startup a large store made long. A push no longer stalls inside its own reply deadline; the snapshot rebuild it triggers now runs between connections. Serving reads the repository through an on-demand log-offset index rather than a resident copy, so peak memory to serve a 67,499-artifact repository fell from about 157 MB to about 32 MB, with clones byte-identical to before.

Also: the end-to-end suite is safe to run concurrently with itself (fresh loopback ports), and the unclassifiable-artifact tolerance rule is now covered by deterministic simulation and an end-to-end scenario. check-in: a469147254 user: dmestas tags: trunk, version-0.1.3

The rule that lets state assembly skip a stored artifact it cannot classify — when the artifact's bytes verify against the name it is stored under — shipped with the fix but was pinned only by two unit tests over hand-built logs, and by a manual clone of the real fossil repository. Neither the simulator nor the end-to-end suite exercised it, so a regression could pass every automated gate.

Deterministic simulation grows an artifact-level generator (src/sim/ assembly_sweep.zig): it emits artifacts whose card sets sit in and around the required-card table — some verifying against their stored name, some stored under a wrong one — and asserts the split directly, that assembly completes iff every unclassifiable artifact verifies, derives no state from one, and stays fatal on a single artifact whose bytes do not match its name. It runs every seed. assembleState is made public for it to drive; its body is unchanged.

The e2e suite gains a scenario that clones a served store carrying an anonymous wiki artifact (cards D L W Z, no U — the shape that first surfaced this) and asserts update tolerates it, with the read verbs and assembly agreeing on the same store. Reverting the verify-then-skip arm to an unconditional failure reddens the sweep, the e2e scenario, and both unit tests. check-in: c2851f933e user: dmestas tags: trunk

Priming a serve snapshot copied every artifact's container out of the log into an in-memory store and held them there for the server's lifetime. The log had already been scanned and every frame CRC-checked to build the rid table, so the copy was a second full read whose only product was resident bytes: on a 254k-artifact repository it was two thirds of the prime time and a few hundred megabytes of RSS, all to re-hold what the log already holds.

The snapshot is now a log-backed store: an index of hash -> log location, and container bytes read from the log on demand as a round emits them, memoised only for the round and released after it. Persisted order is preserved so the clone pager still cursors correctly, the binary-digest to hex-wire-name conversion stays at its one site, and a read fault after the scan surfaces as a server storage error so a clone is never silently truncated. The old whole-store copy is retained only where it is actually needed: the pull client's holdings and the equivalence test's oracle.

Measured, 67499-artifact repository, ReleaseSafe: a clone off the indexed serve is byte-identical to a clone off the copy-based serve (both materialise all 983 files of trunk identically), while serve peak RSS falls from 157 MB to 32 MB. The one remaining O(store) cost, the startup scan itself, is a separate change. check-in: e17845e40d user: dmestas tags: trunk

zit serve built its whole in-memory snapshot of the repository before it opened the listener socket. The build is O(store), so past a few thousand artifacts it outlasted the client's readiness probe and the client reported the server never came up — the store could be served, just never reached.

Bring-up now binds first: listen, announce, then prime, then accept. A client that connects during the prime queues in the kernel accept backlog instead of being refused, so the readiness window starts at the bind rather than after the scans. The listener open moves ahead of BOTH O(store) reads on the path — the config read and the prime. The connection deadline is armed only on accept, so priming never falls inside it. On a 254k-artifact store a connect now completes in ~2 ms against a ~5 s prime.

A push made the snapshot stale, and the old code rebuilt it inside the pushing round's own reply deadline — an O(store) rebuild charged to the request that caused it. The rebuild moves to a maintain hook the accept loop runs between connections, with no connection open to charge it to; the append-only stat gate makes the stale snapshot self-correcting until then.

The reorder is inherently a large-corpus latency property: reverting it leaves every unit test green, because the failure only shows when prime latency exceeds the readiness window. It is pinned in the milestone tier instead, where smoke already lives: zig build bench -- serve synthesizes a store, spawns the real server, and asserts time-to-first-connect is a small fraction of the prime (fixed order ~0.1; reverted order jumps past 1.0). The de-race and the accept-loop hook are pinned by ordinary unit tests. check-in: de218fa6f6 user: dmestas tags: trunk

The 'cli push' and disconnect-robustness scenarios bound a fixed loopback port, so two e2e binaries running at once — the ordinary case under a parallel build or a busy CI runner — collided on it and one push exited non-zero, failing an unrelated-looking assertion. The failure was invisible because the assertion reported only the child's exit code and discarded its stderr.

Each scenario now draws a fresh port from the kernel (bind :0, read back the assigned port, release) and waits for the child to accept before driving it, the same approach freshLoopbackPort takes for the Fossil smoke tests. The push assertion now surfaces the child's stderr on failure, so the next divergence is diagnosable rather than merely counted.

Verified on Linux under the exact condition that reproduced the flake: two 'zig build e2e' runs in parallel, ten rounds, x86_64 and aarch64 — 20 of 20 green on each, where the fixed-port version failed intermittently. check-in: b4a5886252 user: dmestas tags: trunk

Regenerated from the RFC suite after the erratum repo-state-00-s4-unclassifiable-artifact was applied. New §4.4 states what assembly does with a stored artifact classification rejects: an artifact whose octets hash to the name it is stored under is opaque to repository state and MUST NOT fail the assembly, while one whose octets do not hash to its name is a distinct integrity failure and MUST be rejected. The remaining §4 subsections renumber behind it.

The draft was previously silent on this, and that silence was the trap: an implementation conforming to both drafts could reject an artifact per the required-card rule and then treat that rejection as fatal, which made the canonical fossil repository unassemblable. src/update.zig implements the rule this text now carries. check-in: 42e1faa9fc user: dmestas tags: trunk, version-0.1.2

The 0.1.2 release check-in carried the version bump and the README pointer but not the notes themselves: the add that would have tracked them was refused by a locked checkout database, and the refusal was hidden behind a pipe that kept only the last line of output. The file existed on disk and in no commit. check-in: aabc10268a user: dmestas tags: trunk

Two defects made zit unusable against a repository of real size and real history. Serving a sync round cost work proportional to the served store rather than the request, so past a few thousand artifacts a round outran the connection deadline and the server answered nothing at all. Repository-state assembly rejected an entire repository over one stored artifact it declined to classify, while every read verb skipped the same artifact.

Together they meant a clone of the canonical fossil repository could be fetched but not used. It now clones in 67 rounds and materialises all 983 files of the check-in, each byte-identical to fossil's own checkout of it. check-in: 800caecbf2 user: dmestas tags: trunk

A conforming repository contains artifacts a conforming parser declines, and assembly rejected the whole repository over one of them while every read verb skipped it. Bytes that hash to the name they are stored under are stored correctly and merely unclassifiable, so they are opaque to state and skipped; bytes that do not are an integrity failure and stay fatal.

This closes the tolerance half of the update-diagnostics work. On a clone of the canonical fossil repository, update now materialises all 983 files byte-identical to fossil's own checkout. check-in: 6a0f1f3f66 user: dmestas tags: trunk

A conforming repository contains artifacts a conforming parser declines. The artifact grammar requires the U card on a wiki artifact; fossil elides it when the submitter is "nobody", stores the result and syncs it. A clone of the canonical fossil repository therefore carries such artifacts, and assembly rejected the whole repository over one of them while timeline, ls, info and branch read the same store correctly.

The two conditions are separated by the name. Bytes that hash to the name they are stored under arrived and were stored correctly, so the only event is that this reader's grammar does not admit them; the artifact is opaque to state and is skipped, exactly as a non-participating type already is. Bytes that do not hash to their name are an integrity failure and stay fatal. Verification runs before the skip, which is what keeps the second from being swallowed by the first.

On a clone of the fossil repository, 67499 artifacts: update went from exit 1 having materialised nothing, to materialising all 983 files byte-identical to fossil's own checkout of the same check-in. closed check-in: f4736670a8 user: dmestas tags: fix10-tolerance

Two costs made a clone of a large repository O(rounds x store) of work; past a few thousand artifacts a round outran the connection deadline and the server answered nothing at all.

The reply's advertise walk classified every rid by calling content(), which INFLATES a wire-backed entry, so announcing the store cost its uncompressed size every round. It now reads held(), answering from the retained form alone. The send gate still reads content(): uploading composes from plaintext.

ServeCtx caches the snapshot and rebuilds only when a stat shows the log grew, so a commit made alongside a live server is still advertised next request. That rebuild is O(store) and stays out of every client's budget: serve primes before it listens, and a round that appends rebuilds before returning. Reuse needs isolation, since the responder interns phantoms as it answers, so a new OverlayStore gives each round a write overlay. Inflating memoises, so a snapshot outliving its round accumulates the whole repository's plaintext; it is released per round.

The one conflict, at the tail of src/cmd/sync.zig, was two independent test appends; resolved as the union. check-in: 6763d35da7 user: dmestas tags: trunk

update, open, merge and bisect collapsed ApplyError.StateRecordInvalid and ApplyError.Corrupt onto one line, "cannot read repository: repository is corrupt". Corrupt means stored bytes do not match the name they are stored under. StateRecordInvalid means only that a stored artifact was not usable as a check-in state record, which says nothing about integrity. An intact fossil clone reaches the second routinely, so update accused an undamaged clone of corruption while timeline read the same store fine.

StateRecordInvalid now carries its own reason text, shared across the four verbs so they cannot drift or re-merge. The bisect mapper had a blanket else arm swallowing the whole set into the corruption line; it is now exhaustive.

Diagnostics only: assembly still rejects these artifacts, so update still exits 1 on such a clone. The tolerance fix is separate; the shape that triggers it, an anonymous wiki page with no U card, is pinned. check-in: e3bbb4ff22 user: dmestas tags: trunk

Two costs made a clone of a large repository O(rounds x store) of work; past a few thousand artifacts a round outran the connection deadline and the server answered nothing at all.

The reply's advertise walk classified every rid by calling content(), which INFLATES a wire-backed entry, so announcing the store cost its uncompressed size every round. It now reads held(), answering from the retained form alone. The send gate still reads content(): uploading composes from plaintext.

ServeCtx caches the snapshot and rebuilds only when a stat shows the log grew, so a commit made alongside a live server is still advertised next request. That rebuild is O(store) and stays out of every client's budget: serve primes before it listens, and a round that appends rebuilds before returning. Reuse needs isolation, since the responder interns phantoms as it answers, so a new OverlayStore gives each round a write overlay.

Inflating memoises, so a snapshot outliving its round accumulates the whole repository's plaintext. It is released per round. Four clones of 3001 artifacts, ReleaseFast: 12 MB and 0.09 s, against 26 MB and 0.15 s. closed check-in: e2e9233582 user: dmestas tags: fix9-serve-stall

zit update, open, merge and bisect collapsed ApplyError.StateRecordInvalid and ApplyError.Corrupt onto one line, "cannot read repository: repository is corrupt". They are different claims. Corrupt means stored bytes do not match the name they are stored under. StateRecordInvalid means only that a stored artifact was not usable as a check-in state record, which says nothing about integrity.

An intact fossil clone reaches the second routinely: fossil stores and syncs artifacts it declines to crosslink itself. Assembly treats those as fatal while the read verbs skip them, so update accused an undamaged clone of corruption while timeline read the same store fine.

StateRecordInvalid now carries its own reason text, shared across the four verbs so they cannot drift or re-merge. The bisect mapper had a blanket else arm swallowing the whole set into that corruption line; it is now exhaustive over ApplyError.

Diagnostics only: assembly still rejects these artifacts, so update still exits 1 on such a clone. The tolerance fix is separate; the shape that triggers it, an anonymous wiki page with no U card, is pinned. closed check-in: f75dfdfbe7 user: dmestas tags: fix10-update-diag

zit serve rebuilt its whole in-memory snapshot from the log on every request, and classified held-vs-phantom by calling content on every rid, forcing a full inflate of the entire repository per request. A clone cost O(rounds x store) of server work; past a few thousand artifacts one round outran the connection deadline and the server answered nothing at all.

ArtifactStore grows heldCount, the aggregate of the existing non-inflating held predicate, and serve counts with it rather than re-deriving a worse predicate caller-side. ServeCtx caches the snapshot and rebuilds only when a stat shows the append-only log grew, so a commit made alongside a live server is still advertised on the next request.

Reuse needs isolation: the responder interns phantoms and upgrades entries as it answers, and that would change what later rounds serve. A new OverlayStore answers each request over a per-request write overlay, reads falling through, writes confined to the overlay. The persist pass now takes an ArtifactStore.

On 67,499 artifacts: unfixed, no round completes; fixed, one snapshot build then sub-millisecond rounds. check-in: 2874978461 user: dmestas tags: fix9-serve-stall

Harden native Linux filesystem behavior, deterministic repository iteration, update and undo transitions, Fossil smoke-process containment, and the three-platform CI matrix. check-in: be97df0398 user: dmestas tags: trunk, version-0.1.1

The limitations table stopped short of where a reader would look for more detail; it now points at the release notes rather than growing into a second copy of them. The named build steps were missing zig build cov, the kcov coverage report over the test suite. check-in: 7f7828b7d6 user: dmestas tags: trunk, version-0.1.0

The notes named the fossil version smoke passed against, which is a legitimate conformance fact, but then explained CI runner provisioning and told a future editor to reconcile it against a workflow log. That is tooling detail with no place in a document meant to outlive the tooling. The fossil version stands alone as the fact that matters. check-in: 07c840ae4b user: dmestas tags: trunk

The package version and the version the binary prints move from the 0.0.0 development placeholder to 0.1.0, the first tagged release. Both sites carry the same string so the manifest and the running binary never disagree about what this is. check-in: 9e0be2fc75 user: dmestas tags: trunk

The generator only ever emitted strictly increasing, unique modification times, so the equal-second corner -- where two check-ins tie and the name must resolve by DAG ancestry, not hash order -- was covered only by hand-written regression tests. That corner was a real bug once. A new tie mode reuses the previous mtime on a seeded, bounded roll and shapes a reused-mtime check-in as a descendant chain, the exact shape the bug took; the oracle resolves a tie the way production does, by ancestry and then least hash, so a resolver that fell back to hash order is caught. Order comparison is done up to that tie-break, with the two genuinely implementation-defined dimensions skipped under ties and documented. Reverting the real tie-break in a scratch build makes the tie sweep fail where the unique sweep stays green -- proof the simulator now sees the class it was blind to. Default seeds draw no extra entropy, so the existing universe is unchanged. check-in: b354fb5947 user: dmestas tags: trunk

sim/gen.zig emitted strictly-increasing unique mtimes, so the same-second selection tie -- once a real defect, the B1 regression cluster -- was only example-tested, blind to a class that already bit once.

gen.zig gains a tie-permitting mode: a seeded roll reuses the previous mtime, bounded to short runs, and each reused-mtime check-in is shaped as a linear child of the previous one, so an equal-mtime run is a real descendant chain. oracle.zig now computes the documented tie-break in resolveName, tipSlot and openLeafOf -- descendant-before-ancestor over full ancestry, then least artifact hash (repostate.zig ancestryMaximal) -- so a resolution reverting to hash order is caught, not mirrored.

dst.zig runs the tie sweep as additional coverage; the unique sweep is unchanged. Order-independence keeps its total-rule dimensions (leaf set, name resolution) under ties and skips the open-leaf set, whose equal-mtime supersede is implementation-defined (Section 5.3); the Section 6.3 branch representative is first-seen under a tie, checked in the unique sweep only.

Reverting the tie-break to hash order trips the tie sweep at seed 1. closed check-in: c52cc8cc76 user: dmestas tags: h10-ties

Phase 2 only ever proved convergence after the network was fully healed, so a protocol that converges on a perfect wire but livelocks under sustained loss would have passed. A new degraded phase holds a fixed, never-healed drop and duplication rate on both links and drives a fresh session through the same safety, convergence and termination oracles, within a window scaled to the loss rate: a round makes progress only if both its request and reply arrive, so the expected round count grows as one over the delivered-fraction squared, times a safety factor, with the derivation in a recomputable comment. It converges with wide margin -- across many seeds the worst run finished in a small fraction of the window at every rate tested -- so there is no livelock. Pinning the window below the real need trips the oracle, so the check is not vacuous. The gate runs one modest rate; the soak sweeps a range. check-in: b8ef4a68e5 user: dmestas tags: trunk

The loss-scaled convergence window used divCeil with a catch unreachable for the divide-by-zero arm, which the precommit guard flags outside tests. The delivered-percent denominator is provably at least one, so plain integer ceil division gives the same bound with no error union. closed check-in: 0fbc9225bf user: dmestas tags: h7-degraded

zit serve accepts one connection at a time and read its request head and body with no deadline, so a single peer that opened a connection and then dribbled or withheld its request pinned the accept loop and starved every other client -- a real availability gap the in-memory fuzzers could not see, since they never touch the socket. The connection now runs under a whole-connection deadline: the request work races a timed sleep, and a peer that misses the deadline is dropped so the loop moves on. The bind is loopback only and the deadline is generous, so a legitimate request -- even at the reply ceiling -- always finishes far inside it; only a stalled peer is shed. Four end-to-end abuses -- a slow-loris head, a half-sent body, a mid-response disconnect, an idle-connection burst -- each prove the server still answers a fresh request and a real clone still converges, and the fix is shown to be load-bearing by wedging with it removed. A per-read idle timeout and a configurable value are left for later. check-in: 56c17d0675 user: dmestas tags: trunk

The sync sweep proved convergence only after the network fully healed, so a protocol that converges on a perfect wire but livelocks under sustained loss would still pass.

Phase 2b runs a fresh session over a wire held at a fixed drop/dup rate, never healed, asserting the same convergence and termination oracles within a window scaled from the loss rate: expected rounds are the clean window over (1 - p_loss) squared per direction, times a safety factor, recomputed in a comment rather than a magic number. No corruption is injected -- a corrupted body is already a lost round.

The protocol converges comfortably: over 200 seeds the worst run took 7, 13, and 18 rounds at 10, 25, and 40 percent loss, against windows of 160, 228, and 356 -- no livelock. The gate joins at 10 percent; the soak sweeps the wider rate set. Pinning the window below the real need trips the liveness oracle, so the check is not vacuous. The liveness-under-faults discipline follows TigerBeetle's VOPR. check-in: 464b82c888 user: dmestas tags: h7-degraded

zit serve accepts one connection to completion before the next (single-threaded, serve.zig), and receiveHead plus the body read blocked with no deadline. A loopback peer that dribbles a request head, half-sends a body, or connects idle and holds could pin the accept loop forever -- the socket read path the exchange fuzzers never reach, covered before only by happy-path interop.

Add a whole-connection deadline: the request work runs on its own unit of concurrency raced against a timed sleep, and draining the loser cancels the blocked read, freeing the loop. A per-read SO_RCVTIMEO is unusable here (the Io backend treats a socket-timeout EAGAIN as a bug). serve binds 127.0.0.1 only, so a legitimate same-host request finishes in milliseconds even at the 512 MiB body ceiling; the 5 s bound never fires on a real client and only sheds a stalled one.

Four end-to-end scenarios abuse a live server over loopback -- dribbled head, half-sent body, mid-response disconnect, idle-connection burst -- and assert with bounded waits that a fresh request is still answered and a clone still converges (sync 3.7). closed check-in: e87fb840d1 user: dmestas tags: h11-serve-socket

The working tree -- the one place a version-control tool can lose a user's data -- had no crash simulation; only the log store did. A new faulty directory layer tears and freezes writes at a seeded crash point, and a sweep replays an update across every crash cut, reopens, and checks four invariants. Three hold: an untracked file the update must preserve is never touched, a crashed update recovers to its target through the undo journal, and the checkout record never names a check-in whose tree did not finish materializing. The fourth does not, and that is the point of the harness: the payload write lands in place rather than through the write-temp-and-rename the metadata already uses, so a crash mid-write can leave a managed file spliced from old and new bytes -- torn, but recoverable. The gate runs the three that hold; the fourth is pinned by a test asserting the splice IS produced, so it flips the day the write is made atomic. Crash-point enumeration follows TigerBeetle's storage model. check-in: 5401ce245f user: dmestas tags: trunk

The storage and network simulations ran off the same seed but never intersected, so no simulated exchange ever crossed a store that could lose its tail. This composes them: the sync client's content is backed by a real log over a tearable file, and between rounds -- on a seeded coin -- the store is crash-restarted mid-persist, reopened to its recovered prefix, and the session resumed with a fresh client. The existing safety and liveness oracles must survive the composition: no corrupt content accepted, the recovered set never exceeds what was held before the crash, and once both the network and the disk heal a fresh session still converges within the bounded window. Green across the gate and a deep 120-seed run; a retained switch that makes recovery accept a torn frame trips the oracle, so the check is not vacuous. The fault-composition follows TigerBeetle's VOPR. check-in: 9b689ebafe user: dmestas tags: trunk

Only two targets asserted that their generator still reaches the interesting outcomes; the other 25 could rot to instant-rejection and pass every no-crash check while testing nothing. Six targets that split into distinct outcomes now carry a reached-outcomes floor above a measured minimum round count -- decode-bounded, target-size, predicates, adversarial sync parsers, logstore open, and unframe each must reach both their accept and reject arms, or the run fails. Thresholds are measured at a fixed seed and re-checked at a second, and each floor is proven to trip when the generator is biased to one arm. Single-outcome round-trip targets carry a one-line exemption instead of a vacuous assert. The measurement also named several generators that under-reach their target's arms; those are recorded for follow-up, not fixed here. check-in: 57d8994848 user: dmestas tags: trunk