flowfile-failure-archaeology

name

flowfile-failure-archaeology

description

Chronicles 25+ major incidents in Flowfile's git history (worker/kernel deadlocks and races, reverted or self-reverted branches, Electron/Tauri packaging breakage, codegen correctness bugs, CI flakiness, security-fix lineage, in-flight save/open and flow-naming churn) with symptom, root cause, evidence commit/PR, and current status, plus a live/stalled-branch inventory and a verified-and-rejected list of already-settled debates — use BEFORE re-fighting a settled battle, before proposing a fix that touches worker transport, kernel lifecycle, sort/join/group_by codegen, flow save/open/naming, Tauri packaging or CSP, CI test ordering/coverage, or version/release tooling, and before trusting an old branch, a `git tag`, or a CLAUDE.md line as current truth without checking here first.

Flowfile Failure Archaeology

Purpose: this is the "have we been here before" file. Scan the quick index below before writing a fix for something that feels familiar — a race condition, a silent revert, a packaging break, a codegen bug. Several incidents below have a matching "verified and rejected" fix that someone already tried and walked back; re-proposing it wastes a review cycle.

All facts here were re-verified against the working tree / git history on 2026-07-03 at commit f6963c77 (repo version 0.12.7). SHAs are copy-pasteable into git show <sha> or git log -1 <sha>.

When NOT to use this skill

• Need the current non-historical contract for a subsystem → flowfile-architecture-contract.
• Actively debugging a live failure ("has this happened before" is a means, not the goal) → flowfile-debugging-playbook.
• Need build/CI/testing mechanics, not why they're shaped this way → flowfile-build-and-env / flowfile-testing-and-validation.
• Need env var / feature-flag semantics, not the incident behind them → flowfile-config-and-flags.
• Adding a new node type, want current conventions not history → flowfile-node-development.
• Want the open TODO/debt backlog rather than closed incidents → not this file.

Quick index (symptom keyword → incident #)

1 worker hangs forever / no timeout / p.join() / result queue · 2 Kafka/Redpanda node or scheduler sync · 3 app version wrong/blank on Windows, importlib.metadata · 4 SQL viz 504, VizSessionRegistry, response_q · 5 "File must end with PAR1", kernel parquet I/O · 6 kernel won't start / double-starts on fast click · 7 Tauri sidecar spawn/shutdown ordering · 8 Windows/macOS E2E always green · 9 macOS codesign / Python.framework notarization · 10 DMG missing files, huge asar, electron-builder bump · 11 anything still says "Electron" · 12 icons/fonts missing only in the desktop app, not web · 13 output path defaults, "." resolves next to the binary · 14 sort/ node output order wrong only in generated code · 15 flow tab title / display name vs filename · 16 save-as / open overwriting an existing flow · 17 upgrading fastapi · 18 adding/renumbering an Alembic migration · 19 CI job slow/flaky, or want pytest-xdist · 20 file-explorer path traversal / sandbox escape · 21 worker transport (HTTP polling vs WebSocket) · 22 GA4 / any connection failing only when flow is opened · 23 Airbyte, in-house fuzzy match, website/ · 24 draggable panels, z-index, overlay resize · 25 run history / flow-version linkage · 26 polars version bump, silent CI hang/timeout, SQLContext + scan_delta deadlock · a git tag or "since v0.9.4" claim → Tag/release gotchas below · an old/unmerged branch that "already does this" → Branch inventory below · lowering the worker poll, the catalog sleep, coverage parallel=true, re-trying the FastAPI bump → Verified-and-rejected below.

---

The 25 incidents

1. Worker result-queue deadlock (#564) — the flagship. Symptom: worker tasks hang forever, no timeout (wide-table calculate_schema, deep query plans trigger it). Root cause: both transports (spawner.handle_task, streaming.ws_submit) joined the subprocess before reading its result queue — a child put()ing a payload bigger than the OS pipe buffer (~64KB) blocks in its feeder thread until the parent reads, so p.join() first deadlocks parent and child. Fix: flowfile_worker/flowfile_worker/spawner.py:20 def drain_result_queue(q, p, timeout=...) polls and bails the moment the child exits without a result; streaming.py:316 calls it via asyncio.to_thread; apply_model_task now put()s before signalling progress 100 so progress == 100 always implies the result is already queued. Evidence: 3857aced "fix(worker): drain result queue before joining child to avoid deadlock (#564)", 2026-07-02; regression test at flowfile_worker/tests/test_result_queue_deadlock.py pushes a >64KB payload through both paths — self-guarded since pytest-timeout isn't installed here. Status: merged. Rule: never p.join() before draining q; any new task func must put() before signalling progress==100.

2. Kafka pushed straight to main, reverted, re-landed as PRs. Kafka connection management lands via PR 572012e1 (#380, 2026-04-02). Next day two commits go direct to main, no PR: fa86d940 "Adding kafka to flowgraph" (also accidentally committed diff.txt, 4144 lines, and current-review.md, 119 lines, straight to main) and b7e0be80 "Adding kafka sync solutions to the scheduler". Both reverted same day (84392a6c, 3ab65033). Work re-landed properly as 434980b3 (#400) and 7be19166 (#404). Status: shipped (own CI workflow, kafka pytest marker). Watch for stray plan/diff files landing on main — recurred (775fda49, f670c126).

3. Windows app_version hotfix chain → root-cause fix. Three escalating hotfixes to init_db.py:update_db_info in ~36h: ff2644d8 (2026-06-23, PackageNotFoundError fallback → hardcoded "0.12.3") → ebeca9a4 (same day, add bare except Exception too) → 95f60158 (2026-06-24, importlib.metadata.version() was returning None, no exception, in the PyInstaller Windows binary — added explicit is None guard). Root-cause fix same day: b21f518c "Centralize version management across all manifests (#547)" — shared/_version.py (__version__ = "0.12.7", get_version()) is now the single source of truth, plus tools/bump_version.py / tools/check_version_sync.py (CI drift gate). Rule: never read app version via importlib.metadata in frozen builds — use shared/_version.py::get_version().

4. VizSessionRegistry response-queue race → 504s under SQL viz. 969dd74d (2026-04-26): two parents sharing a session_key both blocked on the same response_q and stole each other's responses; the correct response for parent B got discarded by parent A's "stale, draining" branch, so B timed out at 115s and 504'd. Fix: per-SessionHandle parent_lock: threading.Lock around put-and-wait in execute(); drain loop replaced by a single get() + hard raise on request-id mismatch. Ten minutes later b9dfed1e fixed a companion field-name drift: worker responses use column_schema, catalog/service.py read data["schema"] and silently fell back to a local read via broad except Exception. Rule: shared mp queues need a per-handle lock (pattern in flowfile_worker/flowfile_worker/viz_sessions.py); grep both sides of worker↔core JSON field names when renaming.

5. Parquet corruption race between host and kernel container (#302). Symptom: "File must end with PAR1" reading kernel input/output. Root cause: write_parquet() can leave data in OS buffers; sharing files between host and Docker container over a mounted volume lets the reader see an incomplete file. Fix: explicit fsync after writing parquet in both flowfile_core/flowfile_core/flowfile/flow_graph.py and kernel_runtime/kernel_runtime/flowfile_client.py. Evidence: 84b8e416, 2026-02-03. Rule: any new host↔kernel file handoff must fsync before signalling readiness — Docker volume mounts don't guarantee write visibility ordering.

6. Kernel double-start race. Start button stayed clickable while a kernel was starting; a double-click fired two starts that collided on the container name. Fixed both layers: UI disables the button mid-flight; flowfile_core/kernel/manager.py::start_kernel treats an already-STARTING kernel as a no-op (f43874bb, 2026-05-26). Rule: guard the state machine server-side; never trust the client to disable the button correctly.

7. Tauri sidecar lifecycle races. 161682ba (2026-05-29, 57 insertions, terse message) hardens spawn/shutdown ordering in src-tauri/src/sidecar/{mod.rs,shutdown.rs} and state.rs right after the Electron→Tauri migration (#11). Pairs with the shutdown ladder (HTTP /shutdown → SIGTERM → SIGKILL) and the macOS quit-path fix (Cmd+Q fires RunEvent::Exit not ExitRequested; sidecars leaked until lib.rs matched both plus a parent-death watcher). Status: still the most fragile part of the desktop shell — quit-path desktop E2E is a TODO per the header of flowfile_frontend/tests/web-flow.spec.ts.

8. Windows Electron tests were green while testing nothing (#184). Four compounding anti-patterns made Windows E2E always pass: safety timeout used OR instead of AND across two startup signals; test.skip() instead of throwing on app-launch failure; .catch(() => false) swallowing; an explicit "mark test as passed anyway" branch on unexpected window close. Fix: all four inverted. 09ffc9df, 2026-01-10; follow-up 67e64190 (#187). Status: the suite this hardened was later deleted in the Tauri migration (#11) — fix outlived its own tests. Rule: in Playwright helpers, failures must throw; never test.skip() a broken launch; never force-pass.

9. macOS codesign failure on Python.framework (#266). Electron v36 + electron-builder v26 broke codesign on the PyInstaller-bundled Python.framework ("bundle format is ambiguous") because hardenedRuntime forces --timestamp --options runtime. Fix: signIgnore for Python.framework; CSC_IDENTITY_AUTO_DISCOVERY=false in the CI test workflow. Evidence: 97808864, 2026-01-27.

10. electron-builder v26 DMG breakage + 1GB asar (#269, #271). electron-builder ^26.5.0 → ^25.1.8 (b424fdbf, 2026-01-28): v26.5.0 shipped DMGs missing the Electron Framework binary; also dropped node_modules from the files array (~1GB of dev deps was landing in the asar) and compression "maximum" → "normal" (maximum made asar reads slow). Companion 99c92db1 (#271): vite.config.js → .mjs (ESM-only @vitejs/plugin-react v5 caused ERR_REQUIRE_ESM); pypi-release workflow moved to Node 20. Status: whole Electron toolchain later deleted (#11); lesson generalizes — bundler major bumps repeatedly broke packaging in non-obvious ways.

11. Electron → Tauri migration (#462). 3777c661, 2026-05-30: 100 files, +10,653/−6,621. Deleted the Electron main process (flowfile_frontend/src/main/*.ts) and its whole E2E suite (tests/app.spec.ts, tests/complex-flow.spec.ts, tests/helpers/electronTestHelper.ts). Added src-tauri/, tools/rename_sidecar.py, tools/sign_macos_sidecars.sh. Status: desktop-shell E2E was never re-landed — root CLAUDE.md still calls Tauri-shell E2E via tauri-driver a follow-up, so #8/#9's hardening was discarded with the platform. Some docs pages still say "Electron" — treat any such mention as possibly stale. Aftermath: 8aa1e5c6 (ship .deb only), a812a326 (release matrix), 161682ba (#7), a1e397d1 (#494, overlay), da2a5f2c (#529, see 13).

12. AG Grid icons vanished in Tauri — the CSP trap (#514, #515). Two same-day PRs (2026-06-13) share the literal subject "Fix missing icons in aggrid table viewer" but are unrelated. 3ffa00d0 (#514) is the real fix: src-tauri/tauri.conf.json's CSP lacked font-src 'self' data:, silently blocking AG Grid's icon font only in the desktop webview (fine in npm run dev:web) — current CSP includes it, verify with grep -n csp flowfile_frontend/src-tauri/tauri.conf.json. 4913e27a (#515) reused the title but is actually perf: include_output: bool = True added to FlowNode.get_node_data / GET /node so the settings panel opens instantly instead of computing output-schema prediction. Rule: a desktop-only rendering bug → check tauri.conf.json CSP first; don't trust PR titles here — read the diff.

13. Writing output next to the app binary killed the worker (#529). da2a5f2c, 2026-06-19, issue #526: a . default output path resolved to the app install location; writing there crashed the worker with an opaque error. Fix: default output location is now the user's home directory. Windows/desktop path handling is a repeat offender — see also 082a0136 (#496).

14. Sort codegen silently flipped Descending → ascending (#544). The generator computed descending = (how == "desc"), but visual sort nodes store how as "Descending"/"Ascending" — generated Polars code sorted ascending for a Descending sort, inverting downstream logic with no error raised (the executed graph was correct; only exported code was wrong). Fix: centralized parsing in flowfile_core/flowfile_core/schemas/transform_schema.py:952 def is_descending(how) (+ SortByInput.descending property at line 970), accepting both spellings, used by both codegen (sort + window order_by) and the execution engine, which previously each carried their own copy. Evidence: eac45a01, 2026-06-22. Status: fixed — part of a larger codegen-bug family with the same root pattern (71851cd5 #223, dd521299 #224 join codegen, 65153e0b #512 alias bug, d723e0de #549, 6cd67c4a #553 group_by, a96ab2bf #503). Rule: the visual graph and generated code are two separate executors of the same settings — every codegen change needs an equivalence test against real execution; enums with two spellings need one shared parser, not per-consumer copies.

15. Flow-naming saga — attempted fix, self-revert, current live branch. 2026-04-22, branch claude/fix-flow-tab-display-kM4qD: f060a2e8 "fix: use catalog registration name for flow tab titles", self-reverted the same session (e339ffcb), never merged. As of 2026-07-03, branch improvement/improve-naming-unnamed-flows (unmerged, 1 ahead: fa23a297) would change handler.py: create_flow_name() returns a friendly "Unnamed flow YYYY-MM-DD HH:MM:SS" (main today still returns the old "%Y%m%d_%H_%M_%S_flow.yaml", verified at handler.py:25-27); a new create_unnamed_flow_filename(flow_id) produces Unnamed_flow_<ts>_<flow_id>.yaml for the on-disk path ("registration dedupes on path, not name"). On main today, unnamed flows already live under storage.unnamed_flows_directory — display name and path are already loosely coupled; the branch tightens it further. Rule: check this branch before re-deriving a naming design; it isn't merged, don't treat its shape as final.

16. Save/open overwrite saga (still in flight). 1133cc77 (#522, 2026-06-16): Save-As handling, SaveDialog, CatalogFlowPicker, +508/−37. 8681308e "Fix open flow overwrite" on branch fix/overwrite-open-flow (2026-07-02, 1 ahead locally): guards in handler.py + new test_flow_dirty_state.py. Origin's copy of that branch has since walked part of it back: b85abc66 "Revert changes to only targeting the catalog" (deleted 81 lines of the dirty-state test, stripped handler/routes changes) and dc9ff9bb "Revert changes in routes.py", both 2026-07-03 — an ambitious dirty-state-tracking approach scoped back to a catalog-only fix. Rule: diff against both the local and origin copy of fix/overwrite-open-flow before writing new save/open logic — it overlaps handler.py with #15, so landing either branch first changes the merge conflict the other hits.

17. FastAPI upgrade attempted and reverted — main never moved. eff7287b "Reverting upgrade Fastapi" (2026-05-11) exists only on branch feature/LLM-security-patches. fastapi = "~0.115.2" (pyproject.toml line 29) has been unchanged since the file's initial commit. The upgrade was tried during the LLM-safeguards work (which landed separately as f55aa92c #457) and abandoned before merge; the revert message does not record why — treat the cause as genuinely unknown, not solved. Rule: treat the pin as deliberate; budget real investigation time if you attempt this again.

18. Database migrations: born from a production bug, now 28 revisions (root CLAUDE.md is stale). Pre-history: e2977f5c (#422, ~2026-04-08) — a run-type mismatch between local and docker DBs needed a downgrade mechanism, migration 006_normalize_run_type.py, and two tries to align local/worker DBs. Alembic itself arrived in 0ded1ebf (#403, 2026-04-08): alembic.ini, env.py, 001_initial_schema.py, database/migration.py — its own PR body notes "Fix package building with alembic" (bundling it into PyInstaller needed a follow-up fix too). Current count, verified today: flowfile_core/flowfile_core/alembic/versions/ runs 001_initial_schema.py through 028_catalog_namespace_storage.py — 28 migrations. Root CLAUDE.md still says "currently 001–021" — stale by 7 as of 2026-07-03 (v0.12.7). Import-time side effect (database/init_db.py:24-27): importing flowfile_core runs run_startup_migration() unless FLOWFILE_SKIP_STARTUP_MIGRATION is set — always set that before importing flowfile_core outside the running app. Rule: don't trust CLAUDE.md's migration count without re-running ls.

19. CI timing & flakiness arc. f8dbb470 "reverting the test order for now" (2025-04-12) — earliest CI-ordering churn, rolled back. Flaky-test firefighting: 66b14004/e3a2bc80 (2025-04-13, select.vue timing), 49e15434 (2025-09-05, deleted 3 lines from test_endpoints.py rather than fix root cause). 90b8dbb2 (#247) — first parallelization. The big one: 093ead72 "ci: split coverage into its own job with sysmon tracer, drop redundant frontend builds, cancel superseded (#539)", 2026-06-20 — coverage now runs in its own job using Python 3.12's sys.monitoring tracer (COVERAGE_CORE=sysmon, test.yaml ~lines 217-264), redundant build:web calls dropped from backend jobs, a concurrency: block (line 21) cancels superseded runs. The coverage job was ~56min before this change; pytest-xdist was explicitly deferred as high-risk — tests share one SQLite DB. See Verified-and-rejected below before re-proposing xdist.

20. Security-fix lineage. 3c7c42fa (#136, 2026-01-06): path-traversal fix in file endpoints — SecureFileExplorer, sandbox_root, filename sanitization, 403 outside user data dir. 64bca383 (#280, 2026-01-31): that sandbox then broke desktop UX — backend silently returned home-dir contents when navigating above home while the frontend's path state desynced, breaking all subsequent navigation; fix: desktop/Electron mode drops the sandbox entirely, SecureFileExplorer raises PermissionError instead of silently falling back. b4e723f2 (#355, 2026-03-16): hardened flow_data_engine/polars_code_parser.py — a sandbox-escape surface, since user-supplied Polars code runs through it. f55aa92c (#457, 2026-05-11): LLM safeguards + litellm bump; branch feature/LLM-security-patches still holds unmerged follow-ups stalled since 2026-05-11 plus the FastAPI revert (#17). Rule: security fix → silent-fallback regression → explicit-error redesign already repeated once (#136→#280); prefer raising over silently falling back to a safer-looking default.

21. Worker↔core transport evolution (context for #1). 7f9d4768 (#233): HTTP polling with double-base64 → raw-bytes bodies + metadata headers, ~33% bandwidth cut. → 44543f89 (#267): WebSocket streaming for ExternalDfFetcher/ExternalSampler, killing poll latency. → e8b91fa8 (#268): parallel execution via stage-based topological sort (ThreadPoolExecutor within stages). The #1 deadlock is the latest chapter of this same seam — read all four commits before touching worker transport.

22. GA4 / deferred connection resolution (#490). Symptom: a flow whose secrets/connections had gone invalid could not even be opened; GA4 also failed specifically when run from a scheduled workflow. Fix (09f9a2a0 #490 + follow-ups): secrets validate at run time, not open time. Follow-ups fixed three latent races: undo-restore from an empty graph re-stamped connection-backed nodes with user_id=None (fixed by FlowGraph remembering the session owner); memoized credential/Kafka getters ran on a background schema-callback thread concurrently with execution (locks added); stale echoed Kafka fields served stale columns after programmatic updates. Rule: never resolve secrets at flow open, only at run; memoized getters touched by the schema callback must be thread-safe.

23. Removed-feature record (deleted = don't reintroduce). Airbyte connector removed wholesale in aac7177e (#93, 2025-07-29), replaced by native cloud-storage read. In-house fuzzy matching (flowfile_worker/polars_fuzzy_match/*) extracted to the external pl-fuzzy-frame-match package in c1d1d1b2 (#108, 2025-08-22). Landing website website/ added 118132ba (#253) then removed 0086b216 (#260). Electron main process + its E2E suite removed in #462 (see 11). DraggablePanel + 3 panel Pinia stores in WASM removed by 1c549242 (#561); replaced by DraggableItem (see 24). AppHeader.vue deleted #524; aiCompletions.ts deleted #540 (LLM transparency rework).

24. The draggable-panel/overlay saga (longest-running UI pain). Almost a dozen PRs across six months: c224c866 #141 (resize alignment) → 2d31ff35 #198 (z-index bring-to-front) → 47d3f587 #216 (remember position/size) → 5bfaee7b #221 (canvas/panel resize) → 33bc7ef7 #305 (layout not resetting on viewport change) → e3703152 #314 (unbounded z-index growth) → 42094e9d #439 → a1e397d1 #494 (Tauri overlay) → e4b72ff4 #557 (improve dynamic screens) → ed6a12c6 #559 (hotfix sizing) → 1c549242 #561 (2026-07-02) ports the rebuilt DraggableItem system (per-axis resize scale/fill/fixed, tab-strip headers) into flowfile_wasm, deleting DraggablePanel and its three Pinia stores. Branch claude/draggable-item-sizing-kpu3cn (2026-07-01, 1 ahead) continues sizing work on top. Rule: build new overlay work on DraggableItem + drawerRegistry, never resurrect DraggablePanel patterns; z-index growth and viewport-resize regressions are the two failure modes that recurred repeatedly.

25. Run-history fix cluster. 62774106 (#505, 2026-06-11) → 636975c5 (#507, 2026-06-11) → b776bf2c (#501, 2026-06-09) — three PRs in one week on the same subsystem, plus unmerged branches fix/to-flow-version-from-run-history and a typo twin fix/to-flow-version-from-run-histroy (both 2026-06-11, 1 ahead each) and fix/flowfile-lite-run-history-on-error. Rule: run-history/flow-version linkage is fragile — read all three merged commits and check the two near-duplicate branches before modifying this area.

26. Polars 1.43.0 SQLContext-over-delta deadlock (the silent CI hang). Symptom: after bumping polars 1.39.3→1.43.0 (branch maintance/polars-version-bump, PR #617, 2026-07-26), every CI job hung with zero output until the job timeout — kernel job stalled after test_artifact_lineage_kernel_integration PASSED (20 min kill), all five backend matrix jobs (incl. Windows/macOS, no Docker) stalled entering tests/docs_examples/ (40 min kill). Root cause: on polars 1.43.0 + deltalake 1.6.2, pl.SQLContext.execute("SELECT ...") over a registered pl.scan_delta(...) frame deadlocks in Rust while holding the GIL — 5-line repro, main thread, no threads/network needed; plain scan_delta().collect()/collect_schema() are fine. Every catalog SQL reader / virtual view (schema prediction via _add_catalog_sql_reader's SQLContext, view materialization) freezes the whole process — new threads can't even bootstrap (Thread.start() never returns). 1.40.1 / 1.41.2 / 1.42.1 all pass; no upstream issue existed as of 2026-07-26. Silence explained: the hang sites emit nothing before the wedge (fixture write_delta line / runpy of a docs example) and pytest-timeout (1800s) exceeds the CI job timeouts, so no traceback ever printed. Fix: ceiling <1.43 in root + kernel_runtime (lands 1.42.1); same change also caught the kernel image pins in kernel/manager.py still at 0.5.1 after the 0.5.2 bump (masked because CI never reached test_kernel_image_pin_sync.py). Rule: before raising the polars ceiling past 1.42, run the SQLContext-over-scan_delta repro (root CLAUDE.md "Things to Avoid"); and treat a totally-silent CI timeout as "a test wedged before its first log line" — check what the next collected test would be, not the last one printed.

---

Tag and release gotchas

A tag literally named main exists. git show-ref main prints three refs: refs/heads/main and refs/remotes/origin/main at current HEAD, plus refs/tags/main at f6cb5f27 — a January-2026 commit ("Fix Windows Electron build by installing pyinstaller (#185)"). Any command resolving the bare name main (e.g. git log main..branch) warns refname 'main' is ambiguous and may silently resolve to the tag instead of the branch, giving a wildly wrong range. Always write refs/heads/main or origin/main explicitly.

Release tags do NOT stop at v0.9.4 — that's a sort-order illusion. A naive git tag | tail or git ls-remote --tags origin | tail appears to end at v0.9.4 (2026-05-07). This is plain-string alphabetical sort: git tag without -V sorts "v0.10.0" before "v0.9.4" character-by-character ('1' < '9'), so every v0.10.x–v0.12.x tag sorts earlier and gets truncated off a naive tail. Verified today: tags exist up to v0.12.7 (a3ae528e, 2026-07-01) both locally and on origin, tracking the in-repo version closely. Correct check: git tag | sort -V | tail -5 (or git ls-remote --tags origin | awk -F/ '{print $3}' | sort -V | tail -5 for the remote). Rule: if an unsorted tail on tags implies "releases stopped," re-check with sort -V before writing that into any doc or decision — this exact mistake is easy to make.

---

Live / stalled branch inventory

Squash-merging means ~50 local feature/*/fix/* branches remain "ahead" of main even after landing — ahead-count alone does not mean stalled work. Confirmed-live as of 2026-07-03:

Branch	Ahead	Status
improvement/improve-naming-unnamed-flows	1 (fa23a297)	Live, unmerged. See 15.
fix/overwrite-open-flow	1 local; origin has extra scope-back reverts	Live, churning. See 16. Overlaps handler.py with the naming branch.
claude/core-abstraction-flowgraph-001hrn	7, active 2026-07-02	Unmerged: WorkerTransport, ExecutionBackend seam, NodeSpec registry, declarative node builders. If merged, reshapes how nodes/execution are added — pending direction, not current truth.
feature/LLM-security-patches	several	Stalled since 2026-05-11: softened LLM restrictions + the FastAPI revert (17, 20).
fix/ga-4-when-run-from-workflow	3	Leftover — content landed via the #490 squash merge; ignore.

Rule: unmerged claude/* branches are an idea graveyard, not authority. Dozens exist from one-shot Claude sessions and several were deliberately abandoned (e.g. claude/fix-flow-tab-display-kM4qD's same-session self-revert in 15, claude/plan-future-features-*, claude/research-revenue-opportunities-*). A branch that "already does X" is not evidence X is the right design — check why it wasn't merged before reusing it.

---

Verified and rejected — do not re-investigate these

• Lowering the worker's 0.5s poll interval. The hot path is the WebSocket push transport (streaming.py, incident 21), not HTTP polling — polling is a fallback, not the latency-critical path.
• Removing the catalog's ~1.05s sleep in tests (flowfile_core/tests/test_catalog_dashboards.py:194, time.sleep(1.05)). Load-bearing: SQLite's timestamp columns here have 1-second granularity, so two writes in the same second are indistinguishable without it. The ~2s cancel-flow sleeps elsewhere wait out a real polling/settle interval for the same reason.
• Turning on coverage's parallel=true without pytest-xdist and coverage combine. Tried, actively harmful: parallel=true writes per-process .coverage.<host>.<pid> fragments expecting a combine step; without both you get an empty coverage.xml — worse than not setting the flag. xdist itself was deliberately deferred (shared SQLite test DB needs per-worker isolation first) as part of incident 19.
• Upgrading FastAPI off ~0.115.2. Already tried on feature/LLM-security-patches and reverted (eff7287b, incident 17). Reason not recorded — budget real investigation time, don't assume it's a trivial bump.

---

Provenance and maintenance

Re-run these before trusting a fact above that looks stale (verified 2026-07-03 at f6963c77, v0.12.7):

git rev-list --count HEAD                       # commit count (638)
git show-ref main                                # tag-named-main trap
git tag | sort -V | tail -5                      # correct latest-tag check (not `tail` alone)
git ls-remote --tags origin | awk -F/ '{print $3}' | sort -V | tail -5
git log -1 --format='%ad %s' --date=short <sha>  # spot-check any cited commit
grep -n "def drain_result_queue" flowfile_worker/flowfile_worker/spawner.py    # incident 1
grep -n "def is_descending" flowfile_core/flowfile_core/schemas/transform_schema.py  # 14
cat shared/_version.py                           # incident 3
ls flowfile_core/flowfile_core/alembic/versions/ | grep -c '^[0-9]'  # incident 18 (28)
grep -n "currently 0" CLAUDE.md                  # is the migration-count staleness still there?
git log refs/heads/main..improvement/improve-naming-unnamed-flows --oneline  # incident 15
git log refs/heads/main..fix/overwrite-open-flow --oneline  # incident 16
grep -n "time.sleep(1.05)" flowfile_core/tests/test_catalog_dashboards.py  # verified-rejected
grep -n '^fastapi' pyproject.toml                # incident 17

When you land a fix for something chronicled here, or a branch above finally merges or gets abandoned, update its Status in place rather than adding a new incident — one entry per root cause keeps this a lookup table, not a duplicate-riddled log.