Beeper Desktop headless: /v1/chats empty — two root causes (startup-bootstrap null deref + GPU-access Sentry flood) with verified fixes #22

Summary

Running Beeper Desktop 4.2.972 fully headless (Xvfb, no real display) leaves GET /v1/chats returning {"items":[]} even though the profile has synced (384 rooms in index.db), reproducing the same "chats API empty on headless" symptom as #14 and #21. I traced it to two independent, concrete bugs and have a verified fix for both — after applying them the API went from 0 → 25 chats and the inbox processing completes normally.

Both fixes are small and local. Sharing full root cause + repro so a proper fix can ship.

Environment

• Beeper Desktop 4.2.972 (production), AppImage, --appimage-extract-and-run
• Ubuntu 24.04 headless server, no GPU, running under Xvfb :101 + openbox
• Desktop API on 127.0.0.1:23373
• Account fully signed in + E2EE-verified, firstSyncDone: true, all bridges connected, 384 rooms in index.db

Bug 1 — startup-bootstrap throws TypeError: Cannot read properties of null (reading 'length'), renderer never gets seed data

Every launch the main process logs:

[AppStart] renderer-bootstrap-sync: migrations ready, reading bootstrap
[error] [startup-bootstrap] failed to build bootstrap payload TypeError: Cannot read properties of null (reading 'length')

The bootstrap builder (build/main/main-entry-*.mjs, function I'll call buildStartupBootstrap) is, de-minified:

function buildStartupBootstrap() {
  const db = new Sqlite();
  db.init(path.join(dataDir, "index.db"), { readonly: true, fileMustExist: true });
  const raw = db.pluck_get("SELECT value from key_values WHERE key = ?", "startupThreadIDs");
  const ids = JSON.parse(raw ?? "null");            // <-- raw is undefined on a fresh profile → JSON.parse("null") → null
  const rows = db.prepareSQL(threadsByIdSQL(ids.length)).all(...ids);  // <-- ids.length throws on null
  return {
    rawKeyValues: ...,
    initialAccounts: ...,
    initialLabels: ...,
    initialUnions: ...,
    startupThreads: mapThreads(rows),
  };
}

Root cause: the key_values['startupThreadIDs'] row is only ever written by the renderer (setKeyValue("startupThreadIDs", …), VGe(...) in build/renderer/App-*.js) after the inbox has mounted. On a profile that has never had a successful GUI mount (i.e. any headless/server profile), the row does not exist yet, so:

• pluck_get(...) returns undefined
• JSON.parse(undefined ?? "null") → null
• null.length throws
• the whole try/catch returns null, renderer-bootstrap-sync returns no seed data, and the inbox React tree never mounts — which is exactly why mx_room_messages is never processed into the chat-preview layer and /v1/chats stays empty.

It's a chicken-and-egg: the renderer must mount to write the key, but the missing key prevents the mount.

Fix — treat a missing/invalid startupThreadIDs as an empty list instead of crashing:

const parsed = JSON.parse(raw ?? "null");
const ids = Array.isArray(parsed) ? parsed : [];
const rows = db.prepareSQL(threadsByIdSQL(ids.length)).all(...ids);

I confirmed this is the trigger by seeding the row manually
(INSERT OR REPLACE INTO key_values (key, value) VALUES ('startupThreadIDs', '[...20 threadIDs...]')),
after which the startup-bootstrap error disappears on every subsequent launch and the renderer mounts.

Bug 2 — with --disable-gpu (every headless setup), a "GPU access not allowed" error floods Sentry and pegs the CPU, starving chat/message processing

Even with Bug 1 fixed, the main process sat at 100–170% CPU and /v1/chats was still empty. A V8 tick profile (--js-flags=--prof) of the main process:

 [Summary]
   31.4% JavaScript   45.7% C++   23.0% shared libs
 [JavaScript] (hottest)
   29.1%  RegExp: \S*Error:            <-- Sentry stack-trace parser
    0.6%  <anonymous> build/main/init-sentry-electron-*.mjs
 [Bottom up]
   29.1%  RegExp: \S*Error:  ->  init-sentry-electron-*.mjs  (Sentry event pipeline)
   21.5%  __read  ->  init-sentry-electron-*.mjs             (per-event /proc/*/stat metric reads)

strace confirmed the C++/__read half is thousands of openat("/proc/<pid>/stat"...) per second — Sentry gathering per-event process metrics.

Instrumenting Sentry's captureException path revealed the exception being captured in a tight loop:

Error: GPU access not allowed. Reason: GPU access is disabled through commandline
switch --disable-gpu and --disable-software-rasterizer.
    at Object.processEvent (build/main/init-sentry-electron-*.mjs)
    at ... (Sentry event pipeline)

Root cause: headless setups pass --disable-gpu (as recommended everywhere). Chromium then continuously raises GPU access not allowed; Beeper's Sentry Electron integration captures every occurrence, and the stack-trace parser regex \S*Error: (catastrophic backtracking on the large minified frames) plus the per-event /proc metric reads consume the whole core. The renderer is starved, so mx_room_messages → messages → chat-preview processing never completes → /v1/chats empty.

Workaround that fixes it (operator side): don't disable the GPU — use software GL instead:

--use-gl=angle --use-angle=swiftshader --enable-unsafe-swiftshader

(drop --disable-gpu). GPU access is then "allowed" via SwiftShader, the error stops, Sentry goes quiet, CPU drops to ~15–30%, and chats populate.

Proper fix (Beeper side), any of:

1. Add the benign GPU access not allowed error to Sentry ignoreErrors / drop it in beforeSend so it can never flood.
2. Don't request GPU access when --disable-gpu is set (or catch the failure once instead of re-raising it).
3. Rate-limit Sentry captures and/or fix the \S*Error: stack-parser backtracking.

Verified result

Beeper Desktop 4.2.972, headless under Xvfb, with (1) the startupThreadIDs row seeded and (2) launched with --use-gl=angle --use-angle=swiftshader --enable-unsafe-swiftshader instead of --disable-gpu:

• GET /v1/chats → 25 chats with real titles (was [])
• GET /v1/chats/{id}/messages → returns messages
• total Beeper CPU ~16% (was one process pegged at 100%+)
• no more startup-bootstrap errors, no more GPU access not allowed flood

This is very likely the same underlying failure behind #14 and #21 on Beeper Server — Bug 1 (bootstrap on a profile that never mounted a GUI) applies directly; Bug 2 is Chromium-specific so it may differ on the non-Electron server binary, but the "renderer/processing never runs → /v1/chats empty while message search works" shape matches exactly.

Happy to provide full logs, the V8 profile, or test a patched build.