The sidebar stays mounted beneath every overlay/page, and it subscribes to
$sessions + $workingSessionIds — both tick on every streaming token. An
unmemoized SidebarSessionRow re-rendered the whole list (Codicon, labels,
status dots) on each delta, and that churn bled into every overlay opened on
top: Cron, Profiles, Agents, Starmap, Webhooks, Command Center, Settings.
- SidebarSessionRow: memo() with a custom comparator that ignores the pure
id-forwarding callbacks (fresh closures by design) and compares only the
data that changes what the row paints. Rows bail out while siblings stream.
- SessionStatusDot: the 5 $...SessionIds arrays now read via useStoreSelector
returning this session's boolean, so a dot repaints only when ITS OWN
membership flips, not on every array tick.
- Artifacts: stable cellCtx (useMemo) + memoized Primary/Location/Session
cells so a link-title fetch on one row stops re-rendering the whole table.
Measured before/after (2s idle, sessions streaming), sidebar-fed overlays:
Cron 407->~30 wasted, Profiles 732->~80, Agents 132->9, Starmap 188->56,
Webhooks 154->22.
Gating this behind an opt-in was the wrong call. A dev server already
executes arbitrary local JS — vite's module graph, every postinstall in
node_modules — so a loopback debugging port does not meaningfully widen
what a `npm run dev` session can already do, and `perf:serve` has opened
one unconditionally all along.
Requiring the variable also defeated the point: the tooling exists to be
reached for mid-task, and a capability you must remember to enable before
launching is one you don't have when you need it.
So the port opens on 9222 — the same port scripts/eval.mjs and
scripts/perf/lib/cdp.mjs already default to — for any dev-server run.
HERMES_DESKTOP_CDP_PORT stops being an on-switch and becomes an
override: a different port, or `off` to disable.
The hard gate is unchanged and still checked first: a packaged build
never opens the port, and no env value talks it into it. Neither does an
unpackaged `electron .` against dist/, which is how the packaged app
gets smoke tested.
Refusals only log when they contradict something the developer asked for
(a typo'd port, an explicit `off`). Packaged and dist runs are closed by
design and stay quiet.
The renderer is a Chromium page, and apps/desktop already carries a whole
CDP toolkit for it — scripts/eval.mjs, scripts/perf/lib/cdp.mjs with its
shared SELECTORS map, and the diag-*/probe-* family. None of it can
attach to `hgui` or `npm run dev`, because neither passes
--remote-debugging-port. The only launcher that opens one is
`npm run perf:serve`, which is a separate isolated instance rather than
the app you're looking at.
Add HERMES_DESKTOP_CDP_PORT. When set, the shell opens a CDP port on
loopback so that existing tooling can read the live DOM: computed
styles, geometry, which rule actually won.
Three independent gates, all required, resolved by a pure function in
electron/dev-cdp.ts so the policy is testable without an Electron app:
1. not packaged — a shipped build never opens the port, and this is
checked first so no env combination can talk it into doing so;
2. HERMES_DESKTOP_DEV_SERVER present — an unpackaged `electron .`
against dist/ is how the packaged app gets smoke tested, so it
behaves like the packaged app here;
3. the port explicitly requested and a valid integer.
Default `npm run dev` is unchanged and silent: no port, no nag. An
opt-in that gets refused always logs why, so nobody loses an hour
wondering what isn't listening.
The address is pinned to 127.0.0.1 rather than left to Chromium's
default, and is deliberately not configurable — there's no reason to
expose a renderer debugger off-host and offering the knob invites
someone to try.
scripts/eval.mjs hardcoded :9222 and threw a raw ECONNREFUSED stack when
nothing was there. It now honours the same variable and explains itself.
Switching to a STREAMING session took ~1.4s to settle while an idle
session settled in ~50ms. The autopsy probe named it: the
FIRST_PAINT_BUDGET -> RENDER_BUDGET backfill runs as a transition, an
interrupted transition restarts from scratch, and stream flushes land
every 33-250ms — so the 300-part backfill re-rendered over and over
(measured: 1374ms settle, 30 commits, Primitive.div x2237 for one switch).
Gate the backfill on the thread being idle. The user lands on the live
tail immediately either way; older turns backfill the moment the run
ends, and 'Show earlier' remains the manual path meanwhile.
Measured on the live app (diag-switch-autopsy, real sessions):
switch to idle session ~35-55ms settled (unchanged)
switch to streaming session 1374ms -> backfill deferred; lands at
the live tail like any other switch
Adds diag-switch-autopsy.mjs (per-switch settle/commits/top-renders) and
live-drive.mjs (status/fps/drag one-liners against the running app).
Driving HER real instance (real profile, real transcripts, streams live)
via CDP instead of synthetic tiles finally exposed the remaining stall.
The timeline on a real 60-frame sash drag:
style recalc 2736ms | script 1027ms | layout 89ms
top callsite: pin @ fallback.tsx — 927ms
Two pin-to-bottom ResizeObservers (the bounded tool window's and the
reasoning preview's) pinned on EVERY resize delivery. A sash drag changes
every message's WIDTH once per frame, so each frame ran scrollTop write ->
scrollHeight read across every tool group: a forced write-read reflow
cascade that the render counters could never see (zero React involvement).
Both pins are now height-gated off the RO entry (reflow-free): only
content GROWTH pins. Width-only deliveries return immediately.
Measured on the live app, same drag, before -> after:
fps 11.5 -> 59-60
p95 101ms -> 18ms
slow>33 60/60 -> 1/60
Also in this batch (each was verified live before the next was attempted):
- thread/list: split messageSignature into STRUCTURAL (ids/roles — keys
boundaries + row identity) and WEIGHT (part counts — budget only), and
memoize groups + row JSX. A streamed part-append re-rendered every
turn's boundary via its resetKey prop; explain() measured 540-865
wasted Block renders per drag/stream sample, now {}.
- message-render-boundary: document the structural-only resetKey contract.
- tool/fallback: memoize ToolFallback's part object + ToolEntry/ToolTitle/
ToolGlyph (151 renders each, 100% wasted, on real transcripts).
- use-message-stream: ADAPTIVE flush floor — next flush waits 3x the
measured cost of the last one (33ms floor, 250ms cap), so multi-stream
load degrades text update rate instead of input latency.
- tree-split: preview sash drags with inline flex on the two seam
wrappers, committing the store ONCE on release (fixed-zone sides get
flexBasis only, so a hidden sidebar can't leave a phantom gap).
- debug/: perf-live LoAF long-frame attribution, explain() cascade walker
with changed-hook indices, diag-real-loop/key-latency/switch-trace
probes that drive the real app over CDP.
Typing during 2 live streams: keystroke->paint p50 3.3ms, p95 18.4ms,
zero frames over 33ms. Session switch p50 ~35ms settled; the remaining
~1.3s outlier tail is streaming-session switches (React work-loop, not
style/layout) — next target.
Captures medians of 5 runs for multitab and render-churn so tonight's
wins can't silently regress.
idle-cost is deliberately NOT gated. Its render attribution and idle
commit rate are trustworthy and are what the scenario exists for, but the
drag fps it reports (~0.6fps, p95 814ms) contradicts a direct
single-clock probe of the same gesture on the same build (57fps). I ruled
out sash selection, tile setup, render-counter residue, and a 20s soak,
and could not explain the gap — so the metric ships as a report, not a
gate. Gating CI on a number I can't defend would either fire on a phantom
or mask a real stall.
tier: 'report' is outside GATED ('ci','cold'), so the scenario still runs
and prints but neither compares nor writes a baseline.
withFrames ran its own requestAnimationFrame ticker while the gesture body
independently awaited rAF per step. Two rAF consumers, so the observer's
deltas counted the driver's frames as well as the app's — it reported
~3fps for a drag that a single-clock probe measures at ~23fps, and it
never moved no matter what got fixed underneath.
Timing now comes from the same callbacks the body drives (__MARK__).
This also fixes a silent false-negative on the typing pass: it paced on
setTimeout, so the independent ticker was mostly sampling idle waits
between keystrokes and reported a flat 61fps. On the driving clock the
same interaction reports ~30fps with 27 of 40 frames over 33ms — which
matches the 'typing feels slow' symptom I previously could not reproduce.
TYPE now records __TYPE_TARGET__ and the runner throws when no composer is
found, so a pass that measures nothing fails loudly instead of scoring a
perfect 0 deficit — same guard DRAG already had.
A CDP trace of one sash drag settled what the render counters could not.
I had assumed the remaining cost was layout/paint; it was not:
script 6770ms | style 1866ms | layout 71ms
Layout was never the problem. The top attributable callsite in our own
code was use-resize-observer.ts at 977ms.
Counting the callbacks named the mechanism exactly: 8,620 ResizeObserver
instances constructed, and during a 40-move drag 2,600 callbacks each
carrying exactly ONE entry — 65 separate callbacks per pointermove. Every
consumer owned a private observer, so N elements resizing under a common
ancestor meant N trips through the observer machinery instead of one
batched delivery. With five mounted tiles that is ~100 user bubbles, each
with its own observer, all woken by a width change.
One shared observer with a WeakMap of target -> handlers. Callers keep
their exact contract: a handler observing several elements is still
invoked once with all of its entries, and unobserve happens when the last
handler for an element goes away.
Verified by trace, before -> after:
use-resize-observer 977ms -> 42.5ms (-96%)
style recalc 1866ms -> 1145ms (-39%)
total script 6770ms -> 3929ms (-42%)
Callback count 2,600 -> 43: one delivery per frame instead of 65.
Adds the two probes that found it. diag-drag-trace.mjs takes a real
timeline trace and prints the style/layout/script split plus the top
script callsites — that split is what disproved the layout theory.
diag-ro-storm.mjs counts RO callbacks vs entries, which is what
distinguished 'a few expensive calls' from 'very many cheap ones'.
TreeGroup called useStore($layoutTree) to build its right-click menu's
move/split directions. That subscribes every zone — and therefore every
mounted pane and its entire transcript — to the whole layout tree. A sash
drag rewrites the tree once per frame, so dragging the sidebar re-rendered
all five tiles' message lists on every pointermove, for a context menu
nobody had open.
The directions are only read when the menu renders, so read the tree there
with .get() instead. Same lazy shape the neighbouring `closable` prop
already uses.
Measured over one 60px sash drag with five busy tiles:
commits 83 -> 12
ChatView 150 -> 10 (4465ms -> 353ms)
AuiProvider 9450 -> 630 (9868ms -> 774ms)
TreeGroup 180 -> 12
TreeSplit 90 -> 6
Also fixes an observer effect in the harness: idle-cost recorded render
attribution *during* the timed gesture, and the counter walks the fiber
tree on every commit. That was large enough to hide this 15x reduction
behind an unchanged fps, so timing and attribution are separate passes now
and `record` defaults off.
Adds scripts/diag-drag-churn.mjs — the probe that found this. It reports
the transcript chain (who above the messages re-rendered) plus every atom
that notified, which is what named TreeGroup instead of leaving it to be
guessed at. Notably the atom list came back EMPTY: this was never store
churn, so the render-attribution path was the only thing that could have
found it.
The synthetic gesture oscillated +/-3px, which nets to zero displacement
and can clamp to a no-op — so it reported a confident fps number for a
drag that never moved the sash. Sweeps monotonically now, dispatches
pointer events React's synthetic system accepts (isPrimary/button/buttons),
and records dragTarget + dragMoved so a drag that silently did nothing is
visible in the output rather than passing as a measurement.
Verified: dragMoved now reports 60px where it previously reported 0.
Adds an `idle-cost` scenario for the symptom Brooklyn reported: with a
thread spinning, resizing the sidebar feels slow. It holds N tiles busy,
pushes NO tokens, and measures the renderer's self-inflicted commit rate
plus fps while dragging the splitter and while typing.
It reproduces immediately. Five busy tiles, nothing streaming:
idle commits 17.7/sec (should be 0 — nothing is happening)
drag 1.4 fps p95 812ms, worst frame 1.9s
typing 61 fps (fine — this is specific to resize)
Attributing the drag window showed 105,385 TooltipProvider renders and
~15s of component time across a 60-frame gesture. Cause: `Tip` mounts a
full Radix provider + Tooltip per call site, and there are ~107 of them.
Radix's Tooltip holds real state and Popper subscribes to layout, so an
unrelated interaction re-rendered all of them.
Mounts the machinery lazily instead, on first hover/focus. Tooltip churn
drops ~4x (105k -> 26k) and drag doubles to 3fps.
Note `defaultOpen` on the armed Tooltip is load-bearing: the pointerenter
that armed it has already fired, so Radix never sees it and the tip mounts
silently closed. A test caught exactly that, and now guards it.
3fps is still bad — the remaining cost is the whole transcript
re-rendering per resize frame (MessagePrimitive.Parts 12,600 renders /
10.5s, Block/Ct 24,300 each, all 100% wasted). Separate fix.
Two problems, both found by distrusting the harness's own numbers.
1. The scenario slept a fixed 1s after mounting tabs, then recorded. Boot
and session hydration are not reliably done by then, so a variable
amount of unrelated work landed inside the measurement window. Three
back-to-back runs on identical code spread 2.2x on total_renders and
3.8x on wasted_renders — wide enough that a single-run before/after
delta could be mostly noise. Replaced with a quiesce gate that waits
for commits to hold still before recording, and reports 'quiet:N' or
'timeout:...' so a contaminated run is visible instead of silent.
2. The counter attributed a context-driven re-render as 'wasted', which
pointed at memo() as the fix when memo cannot block context at all.
Adds contextChanged via the fiber's context dependency list, and
excludes it from wasted.
The gate also turned up a finding worth more than the fix: with five busy
tiles and NO driver running, the renderer still commits ~18x/sec. The
report now names the cascade roots (own state changed, props did not)
rather than leaving them to be guessed at — Streamdown re-renders itself
105 times while idle, which is what drives Block/Ct.
Drives the same synthetic multi-tab streaming workload as `multitab`
(publishSessionState per session per flush, no backend, no credits) but
reports render attribution instead of frame pacing — sidebar_renders,
wasted_renders, and wasted_notifies.
Answers 'does the sidebar re-render while an agent is typing' directly.
The existing `stream` scenario measures streaming into an empty thread, which
is exactly the case where per-delta transcript work does not show up. This adds
`--historyTurns`, which mounts a settled transcript and lets it drain BEFORE
the recorders start, so the measurement window contains streaming work only —
and `stream-history`, a report-only preset that turns it on.
Report-only (tier: manual) rather than gated: how much history a host can mount
varies, so the absolute number is not comparable across machines. It is meant
for same-machine before/after runs.
Co-authored-by: Jakub Wolniewicz <frizikk@users.noreply.github.com>
probe-model-picker.mjs times pill-click → menu painted over N rounds;
profile-model-picker.mjs wraps one open in a CPU profile with a
top-self-time table. Both attach to the perf:serve instance.
N session tiles stacked as tabs, all mounted (keep-alive) and all
streaming concurrently through the real publishSessionState path — the
"several PR reviews at once" workload. Frame pacing + longtask metrics,
no backend or credits needed; the workload that exposed both fixes above
and the regression gate that keeps them fixed.
The desktop self-update chain (Desktop -> hermes-setup --update ->
hermes update -> hermes desktop --build-only -> relaunch) rebuilds
Hermes.exe on the user's machine and declared success on bare file
EXISTENCE. A truncated PE (corrupt cached Electron zip / interrupted
extraction or rcedit rewrite / full disk) or a wrong-architecture
unpacked tree therefore shipped as the 'updated' app, which Windows
refuses to load with 'This app can't run on your computer'
(此应用无法在你的电脑上运行) — and the previous working build had
already been wiped by before-pack.mjs, leaving nothing to fall back to.
Fix, in three parts:
- hermes_cli/main.py: post-build integrity gate on Windows
(_ensure_desktop_exe_launchable). Parses the PE header of the freshly
built Hermes.exe — MZ/PE magic, section-table completeness vs file
size (catches truncation), and COFF machine vs the host arch (catches
arm64/x64 mixups). On failure it purges the (likely corrupt) cached
Electron zip, invalidates the content-hash build stamp so the
updater's retry-once genuinely re-downloads and rebuilds, restores
the previous build from the .bak tree when one exists (keeping the
corrupt tree as .corrupt for diagnostics), tells the user the update
was aborted and their old version kept, and exits nonzero.
_desktop_packaged_executable also now prefers a host-loadable PE over
pure newest-mtime when multiple win-*-unpacked trees coexist.
- apps/desktop/scripts/before-pack.mjs: on win32, the previous unpacked
tree is preserved as <appOutDir>.bak (only when it holds the product
exe — partial/corrupt trees still get the plain wipe) instead of
being destroyed, providing the rollback material for the gate above.
Non-Windows behavior is unchanged.
- Behavior-contract tests: tests/hermes_cli/test_desktop_exe_integrity.py
(23 tests — synthetic PE fixtures for truncation/non-PE/arch-mismatch,
rollback semantics, and the build-only exit contract) and 6 new vitest
cases in before-pack.test.mjs for the .bak preservation rules.
Progresses #69179
Adds a full desktop Playwright E2E suite that launches the Electron app
against a mock inference server, exercising the full boot chain:
electron -> hermes serve -> mock provider -> renderer
Includes:
- Mock OpenAI-compatible inference server (mock-server.ts)
- Shared fixtures with sandbox isolation (credentials, HERMES_HOME,
userData, fixed window-state.json for reproducible screenshots)
- Test specs: boot, boot-failure, onboarding, mock-backend-setup, chat,
and packaged-app launch
- Visual regression: expectVisualSnapshot() wraps toHaveScreenshot in
try/catch so diffs are reported without failing the test suite
- CI workflow: xvfb at 1280x1024, baseline cache from main
(--update-snapshots on main, compare on PRs), step summary table with
diff/actual/expected image links, dedicated visual-diffs artifact
- dev:mock script for local fake-provider development
- test:e2e:visual + test:e2e:update-snapshots scripts using cage
- .gitignore: *-snapshots/ (baselines cached in CI, not committed)
* fix(desktop): allow write-build-stamp from non-git checkouts
Stop hard-failing npm pack when neither GITHUB_SHA nor git HEAD is
available (ZIP installs / broken .git). Emit an explicit fallback stamp
instead so local Windows desktop builds can finish (#50823).
* fix(desktop): treat fallback stamps as unpinned; harden Windows install
Keep all-zero fallback commits out of -Commit/--commit pins and fetch
install.ps1 by branch instead. After bootstrap, pin the marker to the
checkout HEAD so isBootstrapComplete accepts it. On Windows, force ZIP
checkout, seed GITHUB_SHA (ASCII-only install.ps1), and avoid the pack
stamp failure.
* fix(install): pin core.autocrlf=false before ZIP-path checkout (#50823 review)
The ZIP-fallback path added in #67643 runs `git checkout -f FETCH_HEAD`
before core.autocrlf gets pinned (which only happened later, on the
shared clone-path config). On Git for Windows -- where core.autocrlf
defaults to true -- that renormalizes the repo's LF text files to CRLF in
the working tree during checkout, leaving the freshly-created managed
checkout dirty versus HEAD and aborting the next `hermes update`. That is
the exact "dirty tree the user never touched" failure the surrounding
code already guards against (install.ps1:1461-1469, 1750-1753).
Move the `config core.autocrlf false` pin to run immediately after
`git init`, before the fetch/checkout. The later idempotent pin on the
shared clone path is retained so git-clone installs are unaffected.
Addresses teknium1's review on #67643 and supersedes it, preserving the
original author's two commits.
Co-authored-by: HexLab98 <8422520+HexLab98@users.noreply.github.com>
* chore(contributors): map austinpickett commit email for attribution
The check-attribution CI gate flagged austinpickett@users.noreply.github.com
as an unmapped commit-author email (introduced by the autocrlf fix commit
on this PR). Add the per-email mapping file as the gate instructs (the
legacy AUTHOR_MAP in scripts/release.py is frozen).
---------
Co-authored-by: HexLab98 <liruixinch@outlook.com>
Co-authored-by: austinpickett <austinpickett@users.noreply.github.com>
Co-authored-by: HexLab98 <8422520+HexLab98@users.noreply.github.com>
Profiling the boot answered "is there a real cold-start win?": no wasteful
hotspot — the renderer does only ~tens of ms of work at mount, no heavy library
(shiki/mermaid/katex/d3/motion) initializes at startup; the rest is Electron
runtime + waiting, near the Electron floor.
It also exposed that the cold-start number was pessimistic: a fresh
--user-data-dir per run means a COLD V8 code cache and worst-case bundle
recompile every launch. Real users reuse their profile. Measured delta:
fresh (cold cache): spawn→interactive ~1.48s
reused (warm cache): ~1.0s
So representative launch is ~1.0s; only first-launch-after-install pays ~+400ms.
- coldStartSamples() reuses one profile (run 0 warms the cache, discarded;
runs 1..N are warm samples), stepping ports + pausing so the single-instance
lock releases. `--cold-fresh` measures the first-launch worst case.
- Re-baselined cold-start with the representative warm numbers.
Net: nothing high-ROI left to optimize. The only lever is shipping a pre-warmed
V8 code cache to make first launch match warm (~400ms, once per update) — real
packaging complexity for a marginal win, deliberately not pursued.
* bench(desktop): measure the full picture — prod build, cold-start, first-token
Stop drip-feeding scenarios: extend the harness to cover the latencies that
actually dominate perceived speed, and measure them on a REAL production build.
- --prod: build a production renderer with the probe included (VITE_PERF_PROBE=1,
off in normal builds) and launch it from dist/. Measures minified React, so
numbers are representative shipped figures instead of ~3x-inflated dev ones.
- cold-start scenario (tier "cold"): launch → CDP → driver → first paint, via a
fresh isolated spawn per run. Captures spawn_to_cdp_ms, spawn_to_driver_ms, fcp_ms.
- first-token scenario (backend tier): Enter → first assistant token painted —
the TTFT latency an agent app is uniquely judged on.
- run.mjs gained --prod (build once), cold-start fresh-spawn loop, and gates
ci+cold tiers against the baseline.
Baseline re-captured on a PRODUCTION build (median of 5), darwin-arm64 — all
green. Representative numbers:
cold-start spawn→interactive ~1.6s, FCP ~0.5s
stream frame p95 22ms, 1 longtask
keystroke p50 2ms, p95 8.7ms
transcript mount 145ms, 82ms longtask (400-msg open)
The prod build also settled the open question from the dev numbers: the
transcript-mount "lead" (221ms longtask in dev) is only ~72-82ms in prod — not
actionable. Measurement did its job.
* bench(desktop): trustworthy cold-start measurement (code-splitting is NOT the lever)
Investigated code-splitting the ~22MB renderer bundle to cut cold start. It is
the wrong fix on both counts:
1. Intentional design: vite.config disables codeSplitting because Shiki emits
thousands of dynamic chunks and electron-builder OOMs scanning them — a
packaging/installer constraint, not an oversight.
2. The data says it wouldn't help. Fixing the cold-start measurement to be
trustworthy and reading the boot composition (prod build):
spawn → interactive ~1.5s
renderer nav → DOMInteractive ~0.8s, → DOMContentLoaded ~1.06s
so the whole 22MB bundle EVAL is only ~0.27s (DCL − DOMInteractive) of the
~1.5s. The dominant costs are Electron/window startup and React app mount —
neither touched by splitting.
The measurement fixes (the real content of this PR — no app change, since the
optimization was rejected):
- Drop HERMES_DESKTOP_BOOT_FAKE from spawned instances — it injected artificial
per-phase boot-overlay sleeps that inflated cold-start (and slowed every run).
- Unique debug/dev port per cold-start run — a just-killed instance can hold
:9222 briefly, so reusing it made CDP attach to the DYING instance and report
garbage (spawn_to_cdp of ~4ms). Stepping the port per run fixes the race.
- Richer boot marks (dom_interactive, dom_content_loaded, main-script size) so
cold-start composition is visible, not just a single number.
- Forward all numeric boot marks from the cold-start loop.
- Re-baseline cold-start with the clean numbers.
A real cold-start win would target Electron startup / app-mount (e.g. V8 code
cache, deferred non-critical mount) — a future pass, now that it's measurable.
Stop drip-feeding scenarios: extend the harness to cover the latencies that
actually dominate perceived speed, and measure them on a REAL production build.
- --prod: build a production renderer with the probe included (VITE_PERF_PROBE=1,
off in normal builds) and launch it from dist/. Measures minified React, so
numbers are representative shipped figures instead of ~3x-inflated dev ones.
- cold-start scenario (tier "cold"): launch → CDP → driver → first paint, via a
fresh isolated spawn per run. Captures spawn_to_cdp_ms, spawn_to_driver_ms, fcp_ms.
- first-token scenario (backend tier): Enter → first assistant token painted —
the TTFT latency an agent app is uniquely judged on.
- run.mjs gained --prod (build once), cold-start fresh-spawn loop, and gates
ci+cold tiers against the baseline.
Baseline re-captured on a PRODUCTION build (median of 5), darwin-arm64 — all
green. Representative numbers:
cold-start spawn→interactive ~1.6s, FCP ~0.5s
stream frame p95 22ms, 1 longtask
keystroke p50 2ms, p95 8.7ms
transcript mount 145ms, 82ms longtask (400-msg open)
The prod build also settled the open question from the dev numbers: the
transcript-mount "lead" (221ms longtask in dev) is only ~72-82ms in prod — not
actionable. Measurement did its job.
Chased the "stream frame p95 = 60ms with ZERO longtasks" mystery to its actual
cause: the default stream chunk had no paragraph breaks, so it grew into one
giant ~22KB block that re-rendered fully every flush — defeating the block
memoization real streaming relies on. Plain text = 21ms; realistic chunk with
`\n\n` breaks (blocks settle, only the tail re-renders) = 23ms. Fixed the
default chunk to model real LLM output; a break-less `--chunk` remains available
as a single-block worst-case stress.
Also hardened the isolated instance so measurements reflect real cost:
- Wait for the gateway socket to actually connect before measuring (a booting/
absent backend's reconnect backoff churns the main thread). Exposed via a new
__PERF_DRIVE__.connected() probe reading $gateway.connectionState.
- Focus emulation + anti-throttle/occlusion flags so a backgrounded perf window
isn't frame-throttled (no OS focus stealing).
- Generation-guarded the rAF frame recorder so repeated runs don't leave
overlapping recorders polluting frame intervals.
Baseline re-captured as the median of 5 --spawn runs (darwin-arm64); all three
CI scenarios now green and stable. Absolute values are dev-build (noted in
_meta) — regression guards, not shipped numbers.
- Resolve the vite CLI via vite/package.json `bin` (Vite 8's exports block
importing vite/bin/vite.js directly — --spawn failed with ERR_PACKAGE_PATH_NOT_EXPORTED).
- Add a post-launch settle so cold-start contention (vite dep pre-bundling,
first backend-connect attempts) doesn't contaminate the first scenario.
- Drop the raw autolink from the default stream chunk (resolvable URLs trigger
link-embed DNS lookups unrelated to render cost).
- Replace seed baseline with real numbers from a darwin-arm64 --spawn run.
keystroke + transcript are clean; stream is a clean single-run capture (the
isolated backend may not connect, and its reconnect churn inflates frame
pacing — re-capture on a connected instance for tighter tolerances).
Replaces the dozen ad-hoc measure-*/profile-* scripts (each reinventing the
CDP client — 4 different copies — plus its own arg parsing, stats, output
path, and none with a baseline) with one framework under scripts/perf/:
- lib/cdp.mjs one CDP client + target discovery + typing + CPU-profile wrapper + DOM selectors
- lib/stats.mjs percentiles, histograms, CPU-profile self-time ranking
- lib/baseline.mjs load/compare/update baseline + regression gate (new capability)
- lib/launch.mjs attach, OR spawn a fully ISOLATED instance
- scenarios/* one module per measurement, registered in scenarios/index.mjs
- run.mjs / serve.mjs, baseline.json, README.md
Isolation solves the long-standing measurement blocker: a running `hgui` held
the Electron single-instance lock, so a second instance quit. `--spawn` /
`perf:serve` launch with their own --user-data-dir (separate lock scope), their
own HERMES_HOME (separate backend/sessions, config seeded from ~/.hermes so it
reaches a chat view without onboarding), and their own --remote-debugging-port.
Synthetic scenarios drive $messages via window.__PERF_DRIVE__, so no LLM credits.
Scenario -> sunset script mapping:
stream <- measure-synthetic-stream, profile-synth-stream, profile-long-stream
stream --real <- measure-real-stream, profile-real-stream
keystroke <- measure-latency, profile-typing, leak-typing
transcript <- (new: long-transcript mount cost)
submit <- measure-submit, measure-jump
session-switch <- profile-session-switch
profile-switch <- measure-profile-switch
CPU profiling is now a cross-cutting --cpuprofile flag, not 5 separate scripts.
CI-tier scenarios (stream, keystroke, transcript) need no backend/credits and
are gated against baseline.json (seed values; re-capture with --update-baseline
on a reference device). Backend-tier scenarios are report-only.
perf-probe.tsx gains loadTranscript() for the transcript scenario. No core
files touched; isolation is via CLI args, not env-gated app changes.
Verified: node --check all modules, tsc, eslint, and a unit smoke of the
stats + regression-gate logic. The end-to-end GUI run (which opens a window)
is left to run interactively via `npm run perf -- --spawn`.
Third profiling round (after #66033 / #66347), targeting the composer
model picker and dialog opens (worktree dialog etc.), measured over CDP
on real 1000+-message sessions.
Backend — model.options took 4.8s cold / 1.8s warm per call, and the
desktop model pill/picker blocks on it every open:
- agent/credential_pool: _load_config_safe uses load_config_readonly().
Every consumer only reads, and the per-call deepcopy was the dominant
cost — list_authenticated_providers calls load_pool() per provider
row, and each load_pool loaded (and deep-copied) the full config
again via get_pool_strategy.
- hermes_cli/config: memoize ensure_hermes_home() per home path. It
runs inside the config lock on EVERY load_config(), paying ~14
mkdir/chmod syscalls per call. The fast path still re-checks that the
home dir exists, so a deleted home is recreated as before; profile
switches hit the new path and re-run. Tests cover both.
- tui_gateway/server: add model.options to _LONG_HANDLERS. It measured
seconds inline on the WS reader thread — while it ran, prompt.submit
and session.interrupt sat unread (same class as #21123).
Together: model.options RPC 4825/1842ms → 426/230ms (measured on the
live desktop backend); build_models_payload in isolation 6.2s → 0.97s
cold, 0.27s warm.
Desktop — every Radix dialog/popover open forced a whole-document style
recalc (Presence reads getComputedStyle on mount), which on a
1300-message transcript cost ~650-730ms per open (CPU profile:
getAnimationName 483ms self). The worktree dialog (⌘⇧B) paid it on
every single open:
- thread/list: content-visibility:auto + contain-intrinsic-size on the
per-turn group wrappers. Off-screen turns now skip style recalc,
layout, and paint entirely; never-rendered turns hold a placeholder
height (auto: remembered real size once rendered) so scrollbar and
anchoring stay stable. Verified over CDP: worktree dialog open 656-
730ms → ~200ms on the same session; stick-to-bottom pin, scroll-to-
top rendering, and sticky human bubbles all intact.
Also: profile-session-switch harness accepts CDP_HTTP (Chrome tends to
squat on 9222).
Verification:
- scripts/run_tests.sh: config, credential-pool, inventory,
model-switch routing, tui_gateway protocol, profiles suites green
(test_profiles has one pre-existing failure on main, unrelated);
new tests for the ensure_hermes_home memo.
- apps/desktop: tsc clean, eslint/prettier clean, thread + session
suites green (326 tests).
- E2E over CDP on the live app: numbers above, plus scroll/pin sanity.
A cold profile switch pays the full pool-backend spawn — Python boot,
port announcement, readiness probe, token adoption — before the
profile's gateway can even open. Measured with the new CDP harness
(scripts/measure-profile-switch.mjs, same family as
profile-session-switch.mjs): click → WS open is ~2.5-2.9s on a cold
profile, ~3-3.6s to a settled sidebar; a warm profile settles in
~0.5-0.8s. The pointer entering a profile square telegraphs the switch
hundreds of ms before the click lands, so start the spawn then.
- store/profile: prewarmProfileBackend(name) — fires the existing
hermesDesktop.getConnection IPC, which is idempotent (ensureBackend
returns the pooled connectionPromise), so the real switch joins the
in-flight spawn instead of starting it. Skips the active gateway
profile, throttles per profile (60s) so drive-by hovers can't spam
spawn attempts, and swallows failures — error UX belongs to the real
switch. No new IPC surface; the pool's existing LRU cap + idle reaper
still bound resource use, and the LRU guard never evicts a
keepalive-fresh backend for a hover spawn.
- sidebar/use-profile-prewarm: pointerenter/pointerleave handlers with
a 120ms dwell so sweeping the pointer across the rail or a
mixed-profile session list doesn't spawn a backend per element
crossed.
- Wired at the three switch surfaces: rail ProfileSquare, the condensed
ProfileDropdown items (extracted ProfileDropdownItem so each row owns
its dwell timer), and SidebarSessionRow (covers cross-profile resumes
from the all-profiles view; same-profile rows no-op inside the guard).
Measured E2E over CDP: synthetic hover on a cold profile square spawns
its backend in the background; the subsequent click settles in ~519ms
vs ~3.0-3.6s unhovered — and any hover shorter than the spawn still
shaves its dwell off the click's wait.
Verification: apps/desktop `npx tsc --noEmit` clean; full
`npx vitest run` 212 files / 1777 passed (new prewarm guard/throttle
tests in store/profile.test.ts); eslint + prettier clean.
Follow-up to #65890 (router transitions off) and #65898 (structural
compare + first-paint budget): profiling the switch path on real 1000+-
message sessions with a new CDP harness showed the remaining freeze is
NOT markdown rendering — it's a forced-reflow cascade from mount-time
layout reads interleaved with style writes across the transcript's
layout effects, plus the first-paint budget cut landing too late to
stop the full-budget commit.
Measured on the two largest local sessions (996 and 1363 messages),
main-thread longtask totals per switch: warm 2450ms -> 557ms and
1158ms -> 194ms; first paint 1690ms -> 444ms. Harness:
scripts/profile-session-switch.mjs (same CDP family as
profile-real-stream.mjs).
- use-resize-observer: drop the synchronous initial callback and ride
the observer's spec-guaranteed first delivery instead (same frame,
after layout, before paint). The sync call ran while the commit's
layout was dirty, so every size read in a callback forced a full
reflow — with one instance per user bubble (measureClamp read
scrollHeight, then WROTE --human-msg-full, re-dirtying layout for the
next bubble), the switch commit thrashed for over a second. Inside RO
timing the same reads are free. Composer metrics (2x
getBoundingClientRect + documentElement style writes) rides the same
fix.
- Same class, same fix at the remaining call sites profiling surfaced:
ExpandableBlock and TerminalOutput (dozens per tool-heavy transcript)
now measure/pin via RO initial delivery; the tool-window and
thinking-preview pins drop their sync pin() call; the thread
timeline's initial active-tick compute joins its existing
scroll-time rAF batching so back-to-back transcript updates coalesce.
- thread/list: cut the render budget in the RENDER phase (state-from-
props adjustment) instead of the post-commit layout effect. The
effect-time cut was too late — on a warm switch React first built and
committed the full 300-part tree, then re-rendered at 60, then bumped
back to 300, so the expensive commit still happened (and on a cold
switch the bump rAF usually fired while the transcript was still
empty, so the prefetched messages rendered at full budget anyway).
The render-phase cut restarts the component before any child renders;
a second trigger handles the cold path where messages land later
under the same sessionKey.
- thread/list: backfill 60 -> 300 inside startTransition so the older
turns' markdown+shiki render is interruptible background work instead
of a synchronous freeze one frame after the switch paints. Functional
Math.max so an urgent "Show earlier" click can't be rebased back down.
- composer focus: skip the rAF/timeout focus retries when the element
is already focused — focus() runs the full focusing steps (forcing
layout) even on the active element, ~585ms per switch on a large
dirty DOM.
- Replace the tautological render-budget test (it re-declared the
constants locally and asserted 60 < 300) with behavior tests of the
now-exported buildGroups + firstVisibleGroupIndex.
Verification: apps/desktop `npx tsc --noEmit` clean; full
`npx vitest run` 210 files / 1763 passed; manual CDP check confirms the
deferred backfill commits the full transcript, stays pinned to bottom,
and "Show earlier" still pages.
Guard staged node-pty ASAR path rewrites so already-unpacked paths are
not rewritten twice. Normalize spawn-helper to mode 0755 in both the
prebuild and locally compiled build/Release staging paths.
Add behavioral coverage for both unpacked path forms and both helper
layouts.
Co-authored-by: zhouwei <zwcf5200@163.com>
Co-authored-by: liuhao1024 <sunsky.lau@gmail.com>
classifyNativeBinary only checked big-endian Mach-O/Fat magic bytes
(feedfacf, feedface, cafebabe). Real Darwin .node files from node-pty
prebuilds are stored little-endian on disk (cffaedfe = MH_CIGAM_64),
so every Darwin prebuild classified as null, and validateStagedBinaries
threw a platform mismatch on macOS — breaking npm run check for every
macOS contributor. CI didn't catch it because runners are Linux (ELF
path was correct) and tests only planted big-endian fake headers.
Add recognition for all six Mach-O/Fat byte orderings:
- MH_CIGAM (cefaedfe) — LE 32-bit
- MH_CIGAM_64 (cffaedfe) — LE 64-bit [the one real prebuilds use]
- FAT_CIGAM (bebafeca) — LE universal
Update makeFakeNode to write LE CIGAM_64 bytes for the darwin fixture
(matching real on-disk format) and add regression tests for all new
magic forms.
stageNodePty received electron-builder's { platform, arch } but unconditionally
copied host build/Release, staging a host binary (e.g. macOS Mach-O) for a
foreign target (e.g. linux-arm64). The fallback rebuild also didn't pass the
target arch to electron-rebuild.
Now:
- build/Release is only staged when target platform+arch match the host
- cross-platform targets with no matching prebuild fail closed
- same-platform different-arch rebuild passes --arch to electron-rebuild
- post-staging validation reads .node magic bytes (ELF/Mach-O/PE) and rejects
any binary whose platform doesn't match the target
Adds stageNodePtyInto() (testable core) and classifyNativeBinary() (pure),
plus 11 regression tests covering the cross-target scenarios.
When neither a prebuild nor a compiled build/Release/*.node is found for
the target platform-arch, stage-native-deps.mjs now runs
electron-rebuild -f -w node-pty to compile one from source before
re-copying build/Release into the staged dist.
This makes the staging script self-sufficient — it always produces a
working native binary dir regardless of whether npm ci --ignore-scripts
skipped postinstall or whether node-pty publishes prebuilds for the
target (e.g. linux-x64 has no prebuild).
Electron 40 ships Node 24.15, where tsx's ESM load hook returns null and
crashes with ERR_INVALID_RETURN_PROPERTY_VALUE. Bundle main+preload via
esbuild for `npm run dev` and always load the JS preload from dist/.
A top-down Memory Graph panel: memories and skills on a radial time axis
(core = oldest, outer rings = newer) with a playable / scrubbable timeline
that builds the map up over time.
- Reveal lives off the React tree (a ref drives the canvas, a nanostore atom
drives the timeline + legend), so a play-through or scrub never re-renders
the panel; paint is coalesced to one rAF and playback is abortable, so even
frantic scrubbing stays responsive.
- Adaptive dated rings: one equal-width ring per POPULATED calendar bucket,
a "nice-tick" count scaled to the span. Constant (orthographic) core/band
scale — more data grows the disk outward (more rings), never thinner.
- A bucket's nodes fill the band inside their ring and ignite staggered by
real timestamp across it (no end-dump), with an EVE-style warp-in; the
camera steps out band-by-band as rings are reached.
- ASCII "computing" core, theme-aware palette with a distinct memory hue,
shared trackpad-gesture primitives.
- Shareable WoW-style "loadout" codes on a generic, reusable codec
(@/lib/loadout: bitstream + DEFLATE + version/checksum frame + base64url).
- Opens from the statusbar and command palette; i18n across all locales.
Deps: d3-force, fflate (drops unused react-force-graph-2d).
`npm run build` ended with `bundle-electron-main.mjs`, which esbuild-bundled
electron/main.cjs and renamed the bundle on top of the tracked source file.
Because every `hermes desktop` runs `npm run build`, each launch rewrote a
checked-in source file (~7.5k-line source -> ~14.8k-line bundle), dirtying the
working tree with a build artifact that `git restore` couldn't keep (the next
launch re-clobbered it) and forcing autostash/restore conflicts on update.
The bundle only existed to inline `simple-git` so the packaged app.asar (which
ships no node_modules) wouldn't crash at launch with "Cannot find module
'simple-git'". Replace it with the mechanism the repo already uses for the
other hoisted runtime dep (node-pty): stage the dependency closure and resolve
it from process.resourcesPath at runtime.
- stage-native-deps.cjs: resolve simple-git's runtime closure (walking
dependencies + optionalDependencies, so a version bump that adds a transitive
dep can't silently reintroduce the crash) and stage it under
build/native-deps/vendor/node_modules/. The `vendor/` nesting is load-bearing:
electron-builder drops a node_modules dir at the ROOT of an extraResources
copy but keeps a nested one.
- git-review-ops.cjs: fall back to the staged
native-deps/vendor/node_modules/simple-git when the hoisted require() fails;
dev runs resolve the hoisted copy and never hit the fallback.
- package.json: drop the bundler from the `build` script so main.cjs is never a
build target again.
- nix/desktop.nix: drop the direct bundler call (the closure rides the existing
`cp -rn native-deps` into $out) and patch process.resourcesPath in
git-review-ops.cjs alongside main.cjs.
- delete scripts/bundle-electron-main.mjs.
Verified: electron-builder's own file filter keeps the full staged closure
(0 dropped), and a packaged win-unpacked build launches with the git-review
pane resolving simple-git from the staged vendor path.
* fix(desktop): resolve electronDist dynamically + self-heal blocked installs
Supersedes the static-path approach (#48081) and the install-step self-heal
(#48082) with a fix that removes the whole failure class instead of chasing each
symptom. Three distinct faults converged into the June desktop-build outage; this
closes all three.
Root cause (the part #48081 left open — "Gap B"):
build.electronDist was a static relative path in apps/desktop/package.json, but
npm workspace hoisting is NOT deterministic — depending on the npm version and
what else is installed, npm nests the workspace-only electron devDep under
apps/desktop/node_modules/electron OR hoists it to the repo root. A static path
matches only one layout, so a clean install intermittently fails with "The
specified electronDist does not exist". #48081 re-pointed the path at the
nested layout (correct today) but electron-builder reads electronDist
STATICALLY, so any future hoist change silently breaks it again — only caught
by a CI invariant, never self-corrected.
Fix:
- scripts/run-electron-builder.cjs: resolve electron the way Node's runtime does
— require.resolve("electron/package.json") walks node_modules from the desktop
project upward and finds electron wherever npm actually put it. The path can
never drift out of sync with the install layout again, on any OS/npm version.
* dist present -> pass -c.electronDist=<abs>/dist so electron-builder reuses
the unpacked runtime (keeps the #38673 fast path that dodges the 26.8.x
missing-binary re-unpack bug).
* dist absent -> omit electronDist; electron-builder fetches Electron itself
via @electron/get honoring electronVersion + ELECTRON_MIRROR.
package.json: builder script now runs the wrapper; the static build.electronDist
is removed (the resolver owns it).
- main.py / install.sh / install.ps1: on a dependency-install failure where the
electron package staged but its dist is missing (electron's install.js
process.exit(1) on a blocked/throttled binary download — #47266/#47917/#48021),
repopulate the dist via electron's downloader (canonical, then npmmirror.com)
and CONTINUE to the build instead of aborting. npm runs postinstall LAST, so
the only casualty is electron/dist; bailing here is what made the pack-time
mirror self-heal unreachable on a blocked network. Hard-fail only when electron
never staged at all (a genuine dependency error).
- The pack-time mirror fallback now retries the build even when the pre-fetch
can't populate the dist: the wrapper lets electron-builder download Electron
itself via the mirror, so the retry is no longer a no-op (it was, when
electronDist was a static path).
The exact 40.10.2 pin (already on main) keeps the third mode — the native
@electron-internal/extract-zip win32 binding that 40.10.3/40.10.4 ship without a
published prebuild — from recurring.
Tests:
- test_desktop_electron_pin.py: replace the static-path-matches-lockfile
invariant with contracts that there is no hardcoded electronDist to drift, the
builder script routes through the resolver, and the resolver uses Node module
resolution + injects -c.electronDist.
- test_gui_command.py: install-failure self-heal continues to build; genuine
(electron-never-staged) install failure still hard-fails; pack retries under
the mirror even when the pre-fetch is blocked.
Salvages/supersedes the overlapping community work in #48003 (sitkarev),
#48012 (omegazheng), #48033 (james47kjv), and #48082.
Co-authored-by: sitkarev <59806492+sitkarev@users.noreply.github.com>
Co-authored-by: omegazheng <zheng@omegasys.eu>
Co-authored-by: james47kjv <220877172+james47kjv@users.noreply.github.com>
* fix(desktop): narrow Electron self-heal to real missing-dist failures
Follow-up on #48091 to remove the remaining misdiagnosis risk from the
installer/build fallback path (#46785 concern): only take the Electron
repair/retry path when Electron's package files are staged and dist is actually
missing/corrupt.
- main.py: add _electron_pkg_staged_missing_dist() and use it to gate install
failure recovery; fail fast for unrelated npm install errors.
- main.py/install.sh/install.ps1: run cache purge + retry only when dist is
missing; do not retry unrelated tsc/vite/build failures under an
Electron-specific narrative.
- install.sh/install.ps1: tighten install-stage self-heal guard to require both
package.json + install.js and missing dist.
- tests: add coverage that install failure hard-fails when Electron dist already
exists, and update retry test to reflect the tightened recovery condition.
Validation:
- Python tests: 64 passed
- install.sh-related tests included in the run
- Real mac build on this machine:
- npm ci at repo root: success
- cd apps/desktop && npm run pack: success
- electron-builder packaged darwin arm64 and used custom unpacked Electron dist
* refactor(desktop): trim electron self-heal helpers and comments
Deduplicate mirror-retry into _try_redownload_electron_dist / shell
counterparts; shorten wrapper and install-script commentary without
changing recovery semantics.
---------
Co-authored-by: sitkarev <59806492+sitkarev@users.noreply.github.com>
Co-authored-by: omegazheng <zheng@omegasys.eu>
Co-authored-by: james47kjv <220877172+james47kjv@users.noreply.github.com>
After the June lockfile regeneration (#46652) floated electron and reshuffled
npm workspace hoisting, the desktop pack fails with "The specified electronDist
does not exist". apps/desktop/package.json pointed electronDist at the repo
root (../../node_modules/electron/dist) while npm now installs electron nested
under apps/desktop/node_modules/electron. The two contradict, so a clean
install can never package the app (Windows + macOS).
- electronDist -> node_modules/electron/dist (resolved relative to apps/desktop,
i.e. the workspace-local install npm actually produces).
- hermes_cli/main.py, scripts/install.sh, scripts/install.ps1: add a runtime
electron-dir resolver that prefers apps/desktop/node_modules/electron and
falls back to the root hoist, so dist checks + the mirror re-download work
under either npm layout.
- patch-electron-builder-mac-binary.cjs: try the workspace-local Electron.app
before the root hoist in the macOS binary-restore fallback (sibling site no
PR touched).
- test: assert build.electronDist resolves to where the lockfile installs
electron, so a future hoist change (root <-> nested) can't silently break it.
Salvages the overlapping work in #48003 (sitkarev), #48012 (omegazheng), and
#48033 (james47kjv).
Co-authored-by: sitkarev <59806492+sitkarev@users.noreply.github.com>
Co-authored-by: omegazheng <zheng@omegasys.eu>
Co-authored-by: james47kjv <220877172+james47kjv@users.noreply.github.com>
electron-builder 26.8.x can stage an Electron.app without its
Contents/MacOS/Electron binary, then fail renaming it to Hermes:
ENOENT: no such file or directory, rename .../MacOS/Electron -> .../MacOS/Hermes
This breaks `npm run pack` and the installer desktop stage before a
launchable Hermes.app exists.
- Point build.electronDist at the already-installed Electron dist so
electron-builder reuses it instead of re-unpacking from cache.
- Add a darwin-only prebuilder patch that restores the missing main
binary from the runtime dist before the rename. Idempotent (marker
guard), soft-fails on shape mismatch, survives node_modules reinstall.
Co-authored-by: ChasLui <chaslui@outlook.com>
A packaged desktop app launches to a blank page with a bare
ERR_FILE_NOT_FOUND when dist/index.html isn't in the bundle (#39484).
This happens when the build step fails (e.g. a stale checkout that
fails typecheck) but electron-builder packages anyway, shipping an
empty dist/.
- build-time: scripts/assert-dist-built.cjs runs at the tail of the
`build` script and aborts before electron-builder if dist/index.html
or the vite JS bundle is missing/empty. Every packaging path
(pack, dist*) inherits it via `npm run build &&`.
- runtime: resolveRendererIndex() now logs a clear 'packaged without a
renderer bundle — rebuild with hermes desktop --force-build' message
when no index.html exists, instead of silently loading a missing path.
- runtime: resolveWebDist() logs when it falls back to an asar-internal
dist that isn't a real directory (the dashboard 404 class, #41327/#39472),
rather than returning an unservable path silently.
Adds scripts/assert-dist-built.test.cjs (node:test) covering the guard.
hermes desktop failed on Linux with an ENOENT renaming
release/linux-unpacked/electron -> Hermes. Root cause is a corrupt
cached Electron zip (~/.cache/electron/electron-*.zip): app-builder
unpack-electron extracts a partial tree from the bad zip that is
missing the electron binary, so electron-builder dies on the final
rename. Re-running repeats the broken extraction, leaving the desktop
app permanently unlaunchable until the cache is manually purged.
- Add _electron_download_cache_dirs() + _purge_corrupt_electron_cache()
to hermes_cli/main.py: validate every electron-*.zip via
zipfile.testzip() and delete corrupt ones; honor electron_config_cache
/ ELECTRON_CACHE overrides with per-OS defaults.
- Wire purge + single retry into cmd_gui packaged-build failure path so
a poisoned download self-heals (electron re-downloads clean).
- Add beforePack hook (apps/desktop/scripts/before-pack.cjs) to wipe the
target unpacked dir before staging, making packaging idempotent across
interrupted runs. Cross-platform, best-effort.
- Tests: corrupt-zip detector, cmd_gui purge/retry/launch path,
no-retry-when-clean path, and node --test for the cleanup helper.
The thread renders virtualized turns in natural document flow with padding
spacers, and @tanstack/react-virtual already adjusts scrollTop itself when an
off-screen turn is measured and its real height differs from the 220px
estimate. With the browser default `overflow-anchor: auto`, native scroll
anchoring corrects that SAME size delta too, so the two double-correct and the
view lurches — most visibly with Windows mouse wheels, whose coarse notches
mount/measure several under-estimated turns per tick (Mac trackpads scroll
~1-3px/frame, keeping it sub-perceptual).
Set `overflow-anchor: none` on the thread viewport so only the virtualizer
compensates. Also adds `diag-scroll-reset.mjs`, a CDP wheel-up repro that A/B
tests the anchor behavior at runtime to confirm the fix.
