cmux NEXT: the agent pane ships every stylesheet it imports, listed from the imports (base red) by teamleaderleo · Pull Request #24161 · manaflow-ai/cmux

teamleaderleo · 2026-10-22T03:59:33Z

Every fleet DEV build (cmux-ci build, pr-capture) and the webview CI shards stop in the agent pane's web step on feat-cmux-next:

error: the agent pane imports webviews/src/ui/wave.css but build-agent-pane-web.sh does not add it to the page's styles

build-agent-pane-web.sh wrote the page's one <style> from a list of sheets kept by hand, and refused any sheet the pane imports that the list missed. So each new CSS import (ContextSection.css, then ui/wave.css from desktop.ts since #23995) stopped the web step, and with it every native capture, until someone added a line (78c71ce did for wave.css; fe14026 added composer/dropOverlay.css the same way while this PR was open). This PR removes the hand-kept list, so the next import can't do it again. It also covers the ContextSection.css case that #23939 fixes for that one file, and the wave.css case of #24141.

What changes

webviews/scripts/agent-pane/bundle.mjs --css-inputs now lists the sheets in the order the page applies them: esbuild's CSS bundle order (import order, each sheet at its first import, a sheet's @import ahead of it) for the graph of --page-styles and then the entry, followed by any sheet only a lazily loaded chunk imports, by path. It used to be a sorted list that only fed the check.
New webviews/src/agent-session/acpmux/pageStyles.ts imports the page's own sheets (the desktop layer, the base layer, the transcript and composer rules), in the old list's order. A component's own import "./x.css" needs no entry: it ships after these, at its first import.
build-agent-pane-web.sh writes the <style> from that list. It drops a sheet's @import of a sibling (the list carries the sibling ahead of it, as git.css before changes.css), skips acpmux/tailwind.css (still compiled and put last), and keeps both guards: every listed sheet's rules are in the page, and no @import reaches it.
dev.tsx and the gallery (dev-server/galleryHost.ts, which used to regex the shell script) read pageStyles.ts, so the dev server, the gallery and the app share one order. The gallery's list puts each sheet after the siblings it @imports (git.css before changes.css), as the page does, so editing git.css reloads the gallery's pane sheet and marks pane entries touched.

Behaviour

None for the app: built on cmux16 at base 972843d and at this head, the whole page output (index.html, pane.js, chunks/, locales/, the highlight worker) is byte-identical (diff -rq).

Takes back

Takes back #22710: its cat .../ui/importCards.css line in the hand-kept list goes with the list; pageStyles.ts imports ui/importCards.css at the same place, and the page still ships it there (output byte-identical).
Takes back #22815: its cat .../ui/glass/glass.css line goes the same way; pageStyles.ts imports ui/glass/glass.css right after desktop.css, as before.

Testing

webviews/test/agent-pane-styles.test.ts asks bundle.mjs for the list as the script does and checks that it holds wave.css, ContextSection.css, ghost.css, git.css and the page-level sheets, that it starts with desktop.css, that git.css comes right before changes.css, that it starts with the gallery's list, and that the built page carries every sheet in the list's order.

Red on base (the test commit alone): bun test test/agent-pane-styles.test.ts fails 2 tests (the list is sorted and has no page-level sheets).
Green on the head: the same command passes 4 of 4 after scripts/cmux-next/build-agent-pane-web.sh (5 of 5 with test/popup-surface-dev.test.ts, which now checks pageStyles.ts).

Observed / Not run

Observed on cmux16 (a blob-less checkout, bun 1.4.2): build-agent-pane-web.sh --check failed with the error above on fbcb3d3 (before 78c71ce) and passes on the head. The head's page output is byte-identical to base 972843d's.
Negative check: an indented @import "./ghost.css" screen; appended to ui/wave.css makes the script exit 1 with "an @import reached the agent pane's styles".
Fleet DEV builds of earlier heads passed the web step and produced the app: c436caaec321f545bb84096b (328523c) and be6439987e581e9e309e48c5 (ea2d75d).
vp fmt --check and vp lint on the changed files pass, as does scripts/cmux-next/prepush-gate.py. test/gallery-touched-rank.test.ts passes.
Not run: the full bun run check and the whole webviews suite (the sparse checkout lacks the Swift packages that some checks read) and the gallery dev server; the PR's CI covers those.

Changelog

none

Agent session: cosmic-gray

🤖 Generated with Claude Code

cursor · 2026-10-22T03:59:37Z

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teamleaderleo · 2026-10-22T04:21:08Z

Bead cx-x7hvd created for this PR by the cmux coordinator.

blacksmith-sh · 2026-10-22T04:53:47Z

Found 58 test failures on Blacksmith runners:

Failures

Test	View Logs
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...and 48 more test failures. View all on Blacksmith: run 39785809015, run 39785808836, run 39785808978

^{Need help on this PR? Tag @codesmith-bot with what you need.}

github-actions · 2026-10-22T05:07:06Z

cmux status _{(one comment, edited in place; each line is updated by the job that owns it)}

Review adc7fa6: HQ feed card · gallery before/after runs · checks

App of this head (app.zip, kept 1 day)

gh workflow run reload-build.yml -R manaflow-ai/cmux --ref feat-cmux-next -f tag=pr24161 -f ref=agent-pane-css-from-imports -f platform=macos -f backend_mode=local

Unclear: web / react-apps-check failed: no known signature; failed step: Check webview test shards.

CI failed on adc7fa6ed1 (run 39785809015 attempt 1): 4 code, 1 unknown.

Job	Verdict	Why
web / react-apps-check (3)	code	a web test failed
web / react-apps-check (2)	code	a web test failed
web / react-apps-check (1)	code	a web test failed
web / react-apps-check (4)	code	a web test failed
web / react-apps-check	unknown	no known signature; failed step: `Check webview test shards`

Failures:

seen on other PRs claimPaint.test.tsx a pooled Settings page claimed by the host reports its paint once its first screen is in: failed (job)
seen on other PRs claimPaint.test.tsx a Settings page loaded fresh reports its first paint once its first screen is in: failed (job)
seen on other PRs agent-pane-peer-chat.test.ts a chat on an SSH machine > counts its running turn from the prompt and offers no machine switch mid-...: failed (job)
seen on other PRs composer-edges.test.ts composer card: appearance.borders = none draws no edge: failed (job)
seen on other PRs composer-edges.test.ts composer card: one hairline edge by default: failed (job)
seen on other PRs composer-foot-pill-inset.test.ts the row's padding is counted from the inset, so only the pill grows, not the text's place: failed (job)
seen on other PRs composer-location-strip.test.ts the chat composer: no hairline across the seam under the strip: failed (job)
seen on other PRs composer-location-strip.test.ts the chat composer: no gap where the strip stands inside the card's corner: failed (job)
seen on other PRs strings.test.ts the settings strings generate with no missing translation: failed (job)
seen on other PRs strings.test.ts every key the page uses exists in all 21 locales: failed (job)
... 21 more in the job logs

Matched log lines

web / react-apps-check (3): (fail) a pooled Settings page claimed by the host reports its paint once its first screen is in [1072.32ms]
web / react-apps-check (2): (fail) the settings strings generate with no missing translation [299.29ms]
web / react-apps-check (1): (fail) rows of an older page fade in once as they come into view; opened and live rows do not [4447.83ms]
web / react-apps-check (4): (fail) a change's picture opens enlarged on a click, and Close closes it [237.03ms]

Not re-run automatically: web / react-apps-check (3), web / react-apps-check (2), web / react-apps-check (1), web / react-apps-check (4), web / react-apps-check are not machine failures.

Written by scripts/ci/classify_failures.py (ci-failure-attribution.yml); signatures are its SIGNATURES table. A machine verdict is the runner's fault, not this PR's; yours means the failing file is one this PR changes, also red on main that main's latest full suite fails the same way, seen on other PRs that it failed on another pull request's run lately.

red: cmux-next checks (god files, concurrency, crash safety, l10n); NEW: red check: Checks job structure (+2 more) is not red on the base 8c31792; do not merge until green; see lane-rules
red: cmux-next page strings generate; base red: the same failure on the base 8c31792; does not block
red: web / react-apps-check (1); no finished base run on 8c31792 to compare; do not merge until green; see lane-rules
red: web / react-apps-check (2); no finished base run on 8c31792 to compare; do not merge until green; see lane-rules
red: web / react-apps-check (4); no finished base run on 8c31792 to compare; do not merge until green; see lane-rules

Gallery before/after for adc7fa6: the capture produced no images (run).

The page build writes its <style> from a hand-kept sheet list, and each new CSS import (ContextSection.css, then ui/wave.css) stopped the web step and every fleet app build. This asks bundle.mjs for the list from the imports (--page-styles), in cascade order, and checks the page carries each sheet. Red on feat-cmux-next fbcb3d3: the list is sorted, has no page-level sheets, and pageStyles.ts does not exist. Agent-Session: https://cmux.com/deeplink/agent?harness=claude&session=01a1603a-6462-72f0-a4b0-6937eb58e4c3&host=cosmic-gray Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

…rom the imports build-agent-pane-web.sh wrote the page's <style> from a hand-kept list and refused any imported sheet the list missed, so each new CSS import stopped the web step and every fleet app build ("the agent pane imports webviews/src/ui/wave.css but build-agent-pane-web.sh does not add it to the page's styles"; ContextSection.css before it). bundle.mjs --css-inputs now lists the sheets in the order the page applies them: the import graph of acpmux/pageStyles.ts (the page's own sheets, the old list's order) and then main.tsx, as esbuild orders a CSS bundle. The script writes the <style> from that list, drops a sheet's @import of a sibling (the sibling ships ahead of it), and still checks every listed sheet ships. dev.tsx and the gallery load pageStyles.ts, so dev, gallery and app share one order. The page is byte-identical to the old list plus wave.css, except that wave.css lands after the listed sheets instead of after glass.css. Agent-Session: https://cmux.com/deeplink/agent?harness=claude&session=01a1603a-6462-72f0-a4b0-6937eb58e4c3&host=cosmic-gray Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

@imports

…siblings Review (codex xhigh) found two gaps. The page guard only caught @import at column 0, so an indented or conditioned one stayed in the <style>, where the browser drops it; it now refuses any @import outside comments, and the sibling strip allows leading whitespace. The gallery listed only pageStyles.ts's direct imports, so an edit to git.css (which changes.css @imports) neither reloaded the gallery's pane sheet nor marked pane entries touched; agentPaneStylesheets now puts each sheet after the siblings it @imports, as the page does, and the test compares the lists unfiltered. Agent-Session: https://cmux.com/deeplink/agent?harness=claude&session=01a1603a-6462-72f0-a4b0-6937eb58e4c3&host=cosmic-gray Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Review (codex xhigh): CSS keywords ignore case, so "@import \"./print.css\" print;" got past the case-sensitive guard and its sheet would ship without its condition. The guard, the sibling strip, the gallery's sibling regex and the test now ignore case. Agent-Session: https://cmux.com/deeplink/agent?harness=claude&session=01a1603a-6462-72f0-a4b0-6937eb58e4c3&host=cosmic-gray Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

teamleaderleo · 2026-10-22T05:47:19Z

Review (codex xhigh, correctness first): SHIP at c3184d5

Codex (xhigh) reviewed the diff over three rounds:

328523c and ea2d75d: BLOCK. The @import guard only matched column 0, and the gallery's list left out git.css, which changes.css @imports, so an edit to it neither reloaded the gallery's pane sheet nor marked pane entries touched. Fixed in 934d72b.
934d72b: BLOCK. The guard was case-sensitive, so @IMPORT "./print.css" print; got through (CSS keywords ignore case). Fixed in c3184d5.
c3184d5: SHIP, with no remaining correctness findings. It confirmed by probing that uppercase and mixed-case conditioned imports are refused and plain sibling imports are stripped, and that git.css still comes right before changes.css.

At this head the whole agent pane output is byte-identical to the base build, and an appended @IMPORT "./ghost.css" print; makes the script exit 1.

teamleaderleo · 2026-10-22T12:56:41Z

cmux-next guards / cmux-next page strings generate is red on 13 of 13 fresh feat-cmux-next PR heads in the last 2:00:00, so it is most likely a base red, not this PR's. The base-reds lane has it; a base merge picks up the fix once it lands.

teamleaderleo · 2026-10-22T12:56:49Z

cmux-next guards / nightly-guards / workflow-guard-tests / release-notary is red on 12 of 13 fresh feat-cmux-next PR heads in the last 2:00:00, so it is most likely a base red, not this PR's. The base-reds lane has it; a base merge picks up the fix once it lands.

teamleaderleo · 2026-10-22T12:57:03Z

cmux-next / cmux-next checks (god files, concurrency, crash safety, l10n) › Checks job structure is red on 13 of 13 fresh feat-cmux-next PR heads in the last 2:00:00, so it is most likely a base red, not this PR's. The base-reds lane has it; a base merge picks up the fix once it lands.

teamleaderleo · 2026-10-22T13:06:35Z

cmux-next / cmux-next checks (god files, concurrency, crash safety, l10n) › No fleet host names in gallery fixtures is red on 10 of 11 fresh feat-cmux-next PR heads in the last 2:00:00, so it is most likely a base red, not this PR's. The base-reds lane has it; a base merge picks up the fix once it lands.

teamleaderleo · 2026-10-22T13:06:49Z

cmux-next / cmux-next checks (god files, concurrency, crash safety, l10n) › No new SwiftUI (macOS UI is AppKit) is red on 11 of 11 fresh feat-cmux-next PR heads in the last 2:00:00, so it is most likely a base red, not this PR's. The base-reds lane has it; a base merge picks up the fix once it lands.

teamleaderleo · 2026-10-22T13:17:14Z

cmux-next / cmux-next web bundles (source-keyed cache) is red on 11 of 14 fresh feat-cmux-next PR heads in the last 2:00:00, so it is most likely a base red, not this PR's. The base-reds lane has it; a base merge picks up the fix once it lands.

cursor · 2026-10-22T13:19:23Z

Bugbot needs on-demand usage enabled

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teamleaderleo · 2026-10-23T01:29:29Z

Orphaned: no activity for 12 h, and no lane holds a lease on it. The orphan sweep could not merge feat-cmux-next in: conflicts in scripts/cmux-next/build-agent-pane-web.sh. Listed for a lane to resolve.

teamleaderleo · 2026-10-26T21:23:49Z

Review (codex gpt-6-astra xhigh, next-review): BLOCK at adc7fa6

scripts/cmux-next/build-agent-pane-web.sh:71: Removing the explicit CSS paths breaks webviews/test/pane-menus-styled.test.ts:20, which still extracts those paths from this script. It now finds zero stylesheets, so shippedCss is empty and the required menu-rule assertions fail. Update that test to consume the new stylesheet source.

teamleaderleo · 2026-10-30T01:30:05Z

Owned by an agent session · session

teamleaderleo · 2026-10-30T01:33:14Z

Closing as superseded. feat-cmux-next 8125a40 (2026-10-25, "the page's sheets are derived from the dev server's entry; no hand-kept list in the script") already removed the hand-kept stylesheet list from scripts/cmux-next/build-agent-pane-web.sh and derives the pane's sheets from its imports in order. That is what this PR set out to do. The open Astra BLOCK here (the pane-menus-styled test reading the old list) does not apply to base.

teamleaderleo added the risk:normal Risk tier (docs/ci/risk-tiers.md) label Oct 22, 2026

teamleaderleo force-pushed the agent-pane-css-from-imports branch from 328523c to ea2d75d Compare October 22, 2026 04:50

teamleaderleo added risk:normal Risk tier (docs/ci/risk-tiers.md) and removed risk:normal Risk tier (docs/ci/risk-tiers.md) labels Oct 22, 2026

teamleaderleo and others added 3 commits October 21, 2026 22:28

teamleaderleo force-pushed the agent-pane-css-from-imports branch from ea2d75d to 934d72b Compare October 22, 2026 05:32

teamleaderleo mentioned this pull request Oct 22, 2026

cmux NEXT New Tab: no entry animations; content appears at once #24383

Merged

Merge branch 'feat-cmux-next' into agent-pane-css-from-imports

7a90c44

Merge branch 'feat-cmux-next' into agent-pane-css-from-imports

adc7fa6

This was referenced Oct 24, 2026

fix(cmux-next): the agent pane bundles harnessStatus.css (nightly-next red) #24870

Closed

gallery: the pane's sheets come from dev.tsx, as build-agent-pane-web.sh derives them (base red: health 0-3) #25018

Merged

teamleaderleo closed this Oct 30, 2026

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