TaskExecutor.execute() had a classic JS async race window. Original:
async execute(task) {
if (this.executing.has(task.id)) return; // check
const assignedAgentId = task.assignedAgentId;
if (assignedAgentId && await this.shouldDeferForHeartbeat(...)) // AWAIT yields
return;
this.executing.add(task.id); // add (too late)
...
}
Two concurrent execute(task) calls (scheduler dispatch + task:moved event
handler + restart-recovery) both:
1. Pass the synchronous has() check (Set is empty).
2. Enter the awaited shouldDeferForHeartbeat call (yields the event loop).
3. Resume and both call this.executing.add(task.id).
4. Both proceed to create the same worktree path.
Production failure shape (FN-4814 + FN-4811, observed within minutes):
01:30:56 [runA-caoe] Worktree created at /...worktrees/bright-mesa
01:30:56 [runB-w23q] Worktree created at /...worktrees/bright-mesa
01:30:58 worktree liveness assertion failed: not_usable_task_worktree
01:31:48 [thirdRun] also fires liveness assertion fail
01:37:48 In-review stall surfaced [no-worktree-no-merge-confirmed]
This is the root cause of the entire FN-4781/FN-4804/FN-4814/FN-4811
cascade. Every other guard added today (FN-4811 active-session gate,
self-healing reclaim defer, validation-failed recovery, silent reclaim
recovery, integrity-warning dedup) was patching SYMPTOMS of the
duplicate-run race. With this fix, the symptoms stop appearing.
Fix: claim the slot synchronously immediately after the has() check,
release it on the heartbeat-defer early-return path. No await happens
between check and claim, so the race window is closed.
Test added under
packages/engine/src/__tests__/reliability-interactions/concurrent-execute-race.test.ts
verified to fail on the prior (a1b1f9aa0) executor.ts and pass on the
fixed version:
- Two concurrent execute() calls produce the SAME number of
createFnAgent invocations as one execute() call (no amplification).
- A second sequential execute() after the first completes IS allowed
(slot was released).
The task must have assignedAgentId set to exercise the race \u2014 without
it, the short-circuit `assignedAgentId && ...` evaluates the left side
to false synchronously, and no await happens.
Full engine suite: 5048+ tests pass. The 7 transient test-file failures
in the broad parallel run are pre-existing flaky real-git tests
(branch-conflicts-zero-unique, branch-conflicts-recovery,
merger-overlap-guard subprocess-guard contention) \u2014 all of them pass
when run alone or as a smaller group, none touch the executor.execute()
path.
Fusion-Task-Id: FN-4811
The reclaimSelfOwnedBranchConflicts sweep was force-pausing actively-running
tasks. Production failure shape on FN-4819:
1. Self-healing sweep runs every cycle and inspects branch conflicts.
2. For FN-4819, inspection classified the conflict as 'tip-already-merged'
(the task's branch tip was already on main).
3. Sweep called removeWorktree({ reason: SelfHealingBranchConflict }).
4. The FN-4811 active-session gate correctly refused: the worktree was
bound to FN-4819/executor (a live agent session was using it).
5. The thrown ActiveSessionWorktreeRemovalError was caught by the outer
reclaim catch block.
6. The catch escalated to AutoRecoveryDispatcher with class
'branch-conflict-unrecoverable'.
7. decision.action === 'pause' marked the task failed + paused +
pausedReason='branch-conflict-unrecoverable' + moved to in-review.
Net effect: the FN-4811 gate (which is correct \u2014 you can't yank a live
worktree) became a regression source because the self-healing sweep
interpreted the refusal as fatal. Tasks that were actively making progress
got paused with a misleading 'branch conflict unrecoverable' error.
Fix: at the top of the per-task reclaim loop in
reclaimSelfOwnedBranchConflicts, check
activeSessionRegistry.isPathActive(task.worktree) and continue for any
task whose worktree is currently bound to a live session. The reclaim
will retry on the next sweep (sweeps run every cycle) once the session
has finished using the worktree. No data is lost, no decision is forced.
Test added under
packages/engine/src/__tests__/reliability-interactions/reclaim-defers-on-active-session.test.ts
covering:
- The skip path: when activeSessionRegistry has a registration for
task.worktree, the sweep MUST NOT call inspectBranchConflict,
removeWorktree, or isUsableTaskWorktree. The task MUST stay in
in-progress, not be marked failed/paused, not be moved to in-review.
- Control: with no registration, the sweep DOES proceed and reaches
inspectBranchConflict (preserving existing behavior).
Full engine suite: 314 files, 5061 tests pass, 1 skipped. Lint clean.
Build clean.
Fusion-Task-Id: FN-4811
Adds integration tests for node settings sync API routes (`routes-nodes-sync.test.ts`), covering the settings push/pull and sync-status endpoints across the dashboard node management API.
Fusion-Task-Id: FN-4816
Fusion-Task-Lineage: 01f1bec6-f1c3-43bc-8854-5c4739f0e736
Symptom found while investigating 'tasks are still struggling': every
in-review task hitting pre-merge deterministic verification failed with
[verification:bootstrap] bootstrap preamble failed (exit 2):
[test-bootstrap] FAILED: workspace dist artifact rebuild did not complete.
[test-bootstrap] command: pnpm --filter @fusion/engine build
Because pnpm --filter @fusion/engine build hit 17 TS errors from a prior
autonomous-agent refactor introducing a RemovalReason enum-like object
and two new audit event types. The bootstrap preamble is run by the
merger before every direct-merge verification, so a broken engine
typecheck blocked EVERY task from merging.
Fixes:
1. Duplicate RemovalReason re-export in worktree-pool.ts
Both and
were present for the same identifier,
producing TS2300 'Duplicate identifier'. RemovalReason is a const
object with derived type (typeof-keyof pattern), so a single value
export covers both kinds; the type-only re-export was redundant.
2. GitMutationType union missing the FN-4811 audit event types
merger.ts and worktree-backend.ts were emitting
'worktree:removal-refused-active-session' and
'worktree:removal-forced-over-active-session' audit events, but the
union in run-audit.ts didn't include them. Added both.
3. self-healing.test.ts vi.mock had wrong RemovalReason keys
The mock only exposed 5 keys (SelfHealing*) but production code
references HardCancel, Executor*, Merger*, PoolPrune, etc. Calls
like removeWorktree({ reason: RemovalReason.MergerPostMerge }) were
getting reason=undefined, producing confusing 'cannot remove
worktree: [vitest] No RemovalReason export is defined on mock'
error messages. Updated the mock to mirror the production const
exactly.
4. worktree-backend.test.ts removeWorktree calls missing required reason
The new contract makes reason: RemovalReason a required field on
removeWorktree's input. Five existing test cases were missing it;
added reason: RemovalReason.MergerCleanup to each.
5. integrity-warning-persisted-dedup.test.ts Settings cast
The test's makeStore helper cast a partial settings object to
Settings; TS rejected the narrowed type. Cast through unknown.
Verification:
- pnpm --filter @fusion/engine build: clean
- pnpm lint: clean
- pnpm build (full workspace): clean
- pnpm --filter @fusion/engine test: 5045 pass, 1 pre-existing
aiMergeTask real-git timeout flake, 1 skipped
With this fix, the verification bootstrap can complete and the merger
can finalize tasks again.
Fusion-Task-Id: FN-4811
The periodic self-healing sweep at
SelfHealingManager.reconcileDoneTaskIntegrity() emits a single
'Integrity warning: done-task finalize evidence is unproven (<reason>)' log
entry per task when the task is in 'done' but has no provable on-main
evidence. Dedup was via an in-memory finalizeUnprovenWarned Set per manager
instance, so every engine restart resurfaced the same warning on the next
sweep — significant noise on done tasks that legitimately lack evidence,
typically residue of FN-4811 contamination (FN-4771/FN-4778 in production).
Adds an optional MergeDetails.integrityWarning = { warnedAt, reason } field
and persists it on the first warning. Both warning sites in
reconcileDoneTaskIntegrity() (the unproven-and-still-mergeable branch and
the unproven-final branch) now consult the persisted record:
- Same reason as persisted → skip re-emitting, just rehydrate the in-memory
Set for in-process consistency.
- Different reason → re-warn (so a *new* classification problem still
surfaces) and update the persisted record.
Tests added under
packages/engine/src/__tests__/reliability-interactions/integrity-warning-persisted-dedup.test.ts
(real-git, 4 cases):
- First sweep: emits warning + persists record.
- Second sweep, same instance: in-memory Set dedupes (existing contract).
- Fresh manager (simulated engine restart) + pre-persisted record:
persisted dedup suppresses re-emission.
- Fresh manager + persisted record with different reason: must re-warn
and overwrite the persisted reason.
Full engine suite: 308 files, 5041 tests pass, 1 skipped. Lint clean.
Fusion-Task-Id: FN-4811
Two follow-ups stacked on the FN-4811 active-worktree liveness gate:
1. Stale conflict-path recovery (FN-4813 production failure)
When 'git worktree remove --force' fails with 'fatal: validation failed,
cannot remove working tree', the worktree directory is missing on disk
and the git admin entry is stale. Without this recovery, every retry of
tryCreateWorktree on a stale conflict path failed 3 times with
'automatic cleanup failed', leaving tasks unable to create worktrees.
cleanupConflictingWorktree now catches that specific error class, runs
'git worktree prune' to drop the stale admin entry, best-effort deletes
the branch, and returns success so the caller can proceed.
Implementation note: the original attempt used existsSync(worktreePath)
as a pre-check, but vitest's vi.clearAllMocks() can leave the existsSync
mock returning undefined, causing the new branch to fire inside tests
that didn't expect it and leading to worker OOM in
executor-worktree.test.ts. The error-class-based catch is robust against
mock state and matches the real production failure signal exactly.
2. Collapsed broken FN-4806 nested branches
The previous FN-4806 refactor (commit 087b1a766) accidentally nested the
genuine 'agent finished without calling fn_task_done after N retries'
failure path INSIDE the silent-recovery branch, meaning ordinary
failures were being silently requeued (no status=failed, no onError, no
retry-budget burn) instead of being surfaced.
Restored the clean two-branch structure:
} else if (retryAbortedDueToReclaim) {
// silent recovery (FN-4806)
} else {
// genuine no-fn_task_done exhaustion: mark failed, onError, burn budget
}
Also clears baseCommitSha on silent recovery (matches the parallel
session-start-failure path's metadata clearing).
Tests:
- Adds 'FN-4811 follow-up (FN-4813): recovers from validation failed'
case to active-worktree-removal-liveness.test.ts (12 total cases).
- executor-recovery.test.ts no-fn_task_done reclaim coverage now
asserts baseCommitSha is cleared.
- executor-recovery.test.ts 'does not mark task as failed when invalid
transition error occurs on completion' regression fixed by restoring
the failure-path branch.
- executor-core.test.ts 'still enforces fn_task_done requirement in
fast mode' restored.
Full engine suite: 307 files, 5037 tests pass, 1 skipped. Lint clean.
Fusion-Task-Id: FN-4811
The executor's conflict-recovery paths (cleanupConflictingWorktree,
handleBranchConflict, and tryCreateWorktree's live-foreign/stale-resolved
branches) could force-remove a worktree even when it was currently bound
to an active executor session. This caused the FN-4781/FN-4804 cascade:
- 'Execution blocked: assigned worktree path disappeared mid-task' as
git deleted the live agent's filesystem out from under it
- Two parallel runs for the same task alive simultaneously, with the
second run started in a fresh worktree while the first was still
holding the old session
- Cross-task log attribution (an FN-4804 runContext writing to FN-4781)
- Post-merge 'branch tip misbound but content found on main via trailer'
rescues firing on every successful merge as the bookkeeping was
corrupted mid-merge
Adds a hard liveness gate centralized in findActiveWorktreeOwner(), which
checks both the in-memory activeWorktrees map and the DB for non-done,
non-paused, in-progress tasks bound to the worktree. The gate fires at
two points:
1. cleanupConflictingWorktree returns false (refuses removal) when an
active owner is found, logging an FN-4811 refusal entry.
2. handleBranchConflict short-circuits to 'sticky' BEFORE invoking
inspectBranchConflict, because some inspection branches force-remove
unconditionally.
When cleanup is refused, the live-foreign and stale-resolved branches in
tryCreateWorktree now FALL THROUGH to the suffix-rename path (rather
than returning null) so the requesting task can still proceed without
disturbing the live owner.
Tests:
- New reliability-interactions backstop at
src/__tests__/reliability-interactions/active-worktree-removal-liveness.test.ts
covers findActiveWorktreeOwner (5 cases: in-memory match, requesting
task excluded, DB-level match, paused exclusion, terminal-column
exclusion, self-exclusion), cleanupConflictingWorktree gate (3 cases:
in-memory refuse, DB refuse, no-owner proceed), and handleBranchConflict
gate (2 cases: short-circuit + inspection-skipped, no-owner proceeds).
- Updates existing executor-worktree.test.ts assertion that was
documenting the bug behavior (force-removing active worktree) to match
the new contract (refuses + falls through to suffix-rename).
Full engine suite: 307 files, 5035 tests pass.
Fusion-Task-Id: FN-4811
The executor's no-fn_task_done retry loop has two reclaim signals
(retryAbortedDueToReclaim=true): (1) pre-retry liveness recheck where the
task DB shows worktree/branch was cleared, and (2) session-start failure
because the worktree path no longer exists. Both are engine self-heal
situations triggered by FN-4546 stale-active-branch reclaim, FN-4742
self-healing removals, or related housekeeping paths — the agent never
got a fair retry attempt.
Previously these surfaced as task status=failed with error
'Worktree/branch reclaimed during no-fn_task_done retry — requeueing',
fired onError, and burned the taskDoneRetryCount budget. Three legitimate
problems followed: tasks accumulated spurious failures in the UI, the
exhausted-budget branch escalated reclaimed tasks to in-review instead of
retrying, and the noise masked the underlying worktree-removal regression
(FN-4811).
Now the reclaim branch silently:
- clears stale worktree/branch metadata so the next pickup creates a fresh worktree
- requeues to todo with preserveProgress
- logs an informational 'engine self-heal, no failure' line
- does NOT set status=failed, does NOT bump taskDoneRetryCount, does NOT call onError
The genuine 'agent finished without calling fn_task_done after N retries'
exhaustion path (retryAbortedDueToReclaim=false) is unchanged.
Tests updated in
packages/engine/src/__tests__/reliability-interactions/executor-no-task-done-vs-worktree-reclaim.test.ts
to assert the new silent-recovery contract on all three reclaim paths.
Fusion-Task-Id: FN-4806
Adds test coverage for multi-node routing in the hybrid executor, specifically covering routing behavior across nodes (FN-4775 Step 3).
Fusion-Task-Id: FN-4775
Fusion-Task-Lineage: d75a91c9-0c6c-421c-8bc9-11586590d6fe
