[Bug]: Settled shelf crashes the app with React #185 when the sidebar filter has more than one project #27168

What happened

The desktop app crashed with "Something went wrong. Minified React error # 185" (Maximum update depth exceeded) after I'd been looking at the Pull Requests page for a while and then switched views. After that the app was unusable: Try again and Reload app both went straight back to the same error, on every route.

Diagnosis

The first crash's stack goes through the olderSettledShelf chunk into React's scheduleUpdateOnFiber → throwIfInfiniteUpdateLoop. The setState that loops is useOlderSettledShelfGrowth (apps/web/src/state/olderSettledShelf.ts:94-96). That effect calls grow(wanted) whenever wanted !== pages, and wanted is a new Map whenever wantedOlderSettledPages decides one more page is needed.

Why reloading doesn't help: whether the Settled shelf is expanded is persisted in localStorage (t3code:sidebar:settled-expanded, apps/web/src/components/Sidebar.tsx:428). The sidebar is mounted on every route, so once the loop has happened with the shelf expanded, every launch and route hits it again. Setting that key to false brought the app back immediately.

The shelf was added in #24723 (Oct 25). No commit to olderSettledShelf.ts / olderSettledThreads.ts since this build changes the growth logic.

What I ruled out / am unsure of:

• Server pagination looks correct: listOlderSettledThreads orders by (settled_at DESC, thread_id ASC) with a matching tie-break cursor. The DB has 403 settled threads, all with distinct, uniformly formatted (24-char ISO) settledAt values, so a cursor that never advances on ties is unlikely.
• For a synchronous loop, the effect has to see wanted !== pages on 50+ consecutive commits. One way that can happen is scopeKey (from olderSettledScopes([...serverConfigs.keys()], scopedProjectKeys)) differing between consecutive renders. requested.scopeKey !== scopeKey then makes pages fall back to NO_PAGES every render, so wanted is always a fresh {env: 1} map and grow fires again. This is a hypothesis, not confirmed; it fits "switched views" as the trigger.
• A second crash a minute and a half later, on a /draft/... route, had a different stack (combobox → P4.setState). It may be a separate loop, or a consequence of the same state; I couldn't tell.

Steps to reproduce

Not deterministic yet. What happened:

1. With the sidebar's Settled shelf expanded (the user has 403 settled threads, so older ones load in pages), open Pull Requests and stay there a while.
2. Switch to another view/project.
3. The app shows React error Add drag-and-drop project reordering to the sidebar #185. Every reload crashes again until t3code:sidebar:settled-expanded is set to false.

Expanding the shelf again and repeating Pull Requests → switch view afterwards did not reproduce it, so the trigger seems to need more than "expanded + switch".

Version

Desktop app 0.1.4-nightly.20261028.3841 (local server reports the same serverVersion). The triage CLI was 0.1.5.

Environment

Linux x64 (Omarchy, kernel 7.2.8), Node v26.12.1, desktop app against the local server on 127.0.0.1.

Evidence

# Crash 1
T3 Code (Nightly) 0.1.4-nightly.20261028.3841
Path: /pull-requests
Time: 2026-10-29T21:22:42.238Z

Error: Minified React error #185
    at Pi (t3code://app/assets/dist-DcfUooDF.js:34:28269)
    at ji (t3code://app/assets/dist-DcfUooDF.js:34:27794)
    at fc (t3code://app/assets/dist-DcfUooDF.js:34:60319)
    at dc (t3code://app/assets/dist-DcfUooDF.js:34:59941)
    at j (t3code://app/assets/olderSettledShelf-DXYTBlPt.js:1:1066)
    at c (t3code://app/assets/olderSettledShelf-DXYTBlPt.js:1:2477)
    at wl (t3code://app/assets/dist-DcfUooDF.js:34:94992)
    at Uu (t3code://app/assets/dist-DcfUooDF.js:34:118178)
    at Hu (t3code://app/assets/dist-DcfUooDF.js:34:117951)
    at Uu (t3code://app/assets/dist-DcfUooDF.js:34:119394)

# Crash 2
Path: /draft/<draft-id>
Time: 2026-10-29T21:24:11.959Z

Error: Minified React error #185
    at Pi (t3code://app/assets/dist-DcfUooDF.js:34:28269)
    at Mi (t3code://app/assets/dist-DcfUooDF.js:34:27842)
    at Cs (t3code://app/assets/dist-DcfUooDF.js:34:53911)
    at t3code://app/assets/dist-DcfUooDF.js:34:53792
    at P4.setState (t3code://app/assets/utils-Ct-AKQrk.js:23:79691)
    at P4.update (t3code://app/assets/utils-Ct-AKQrk.js:23:79762)
    at t3code://app/assets/combobox-Cm1W01vR.js:1:14047
    at wl (t3code://app/assets/dist-DcfUooDF.js:34:94992)

Related issues

None found for the Settled shelf / olderSettledShelf. Earlier #185 loops (#9390, #11308, #12891, #14959, #15120) are closed and involve other components. #26467 is about older settled thread links, not a crash.

Fix applied or workaround

In DevTools (Ctrl+Shift+I) on the crash screen: localStorage.setItem("t3code:sidebar:settled-expanded", "false"), then Reload app. The app loaded normally afterwards. Nothing else was changed on the machine.

Filed by

Claude Code (Claude Opus 5.5, claude-opus-5-5) via t3 triage