iOS build: fix the hot spots that made CI time out, and fail fast on the next one - #2270
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… not blow up IRGen The "Swift tests + iOS build" job went from 5 minutes (b455e0f) to 26 (4302a9c) and then past its 30-minute timeout on every main run since 20:55 UTC Oct 3, which marked main's run "cancelled" and hid its verdict. The log stopped for 27 minutes inside the x86_64 batch "ActivityRunChip … CompactRoster". That batch is not a slow expression. The stuck swift-frontend, sampled, sits in IRGen emitting an outlined destroy for one view type: IRGenSILFunction::emitSILFunction → StructTypeInfoBase<NonFixed…>::destroy → callOutlinedDestroy → MultiPayloadEnumImplStrategy::destroy → forNontrivialPayloads → … forty frames deep. Every compat shim in BackDeployCompat.swift was a `@ViewBuilder` extension on View that branched on `#available`, so each call returned a `_ConditionalContent` whose payloads each wrap the whole view it was applied to: `onValueChange` has three branches and triples the caller's type, the others double it. ChatView.body chains 19 of them (16 before #2208), so its type is ~3^19 the size of the view it describes. The compiler only sees that type when this file and the caller are primaries of the same compile batch: then the opaque `some View` is looked through and the enum is expanded. A 10-core Mac splits the app into 10 batches and never puts the two together (every local build here took 27-36 s); the 3-core CI runner makes 4 batches of 22 files, and batch one holds both. Forcing `-driver-batch-count 4` locally reproduced it: the batch ran 9+ minutes on an M5 before being killed, every other batch finished in 10 s, and the pair {BackDeployCompat, ChatView} alone takes 100+ s while every other {file, ChatView} pair takes 11 s. Each shim is now a ViewModifier that branches over its placeholder content, so a call wraps the view once and the type grows linearly with the chain. Call sites are unchanged. With the fix the 22-file batch compiles in 11 s, the pair in 5 s, and the exact CI command with four batches builds both slices in 39 s here. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
`generic/platform=iOS Simulator` builds arm64 and x86_64, and ONLY_ACTIVE_ARCH=YES is a no-op with a generic destination (checked: still 16 + 16 SwiftCompile tasks). Nothing runs the x86_64 slice — the runner, the UI-test simulators and current Macs are all arm64 — so it only doubled the compile and ran six swift-frontends at once on the 3-core, 7 GB runner. ARCHS=arm64 keeps the one that matters. -showBuildTimingSummary adds per-task-type totals at the end of the log, so the next slow batch is read off the summary instead of inferred from a gap in the timestamps. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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Included review availability: This review used your included allowance. Your plan provides up to 8 included reviews per hour; 4 remain after this review. 📝 WalkthroughWalkthroughSwiftUI availability handling moves into private modifiers, and several iOS views move inline content into private helpers. The iOS workflow adds a source check for availability shims and checks captured build output for type-check diagnostics. ChangesiOS View and Build Updates
Priority: ➖ Normal Estimated code review effort: 4 (Complex) | ~45 minutes Change: Bug fix Suggested reviewers: Merge Risk: 🔵 Low · up to The iOS changes appear to preserve the existing availability behavior, but the CI source check can miss a branch after a block-comment brace. This is a bounded guard gap to address; it does not establish a current app failure. Architecture SummaryArchitecture risk: 🔵 Low · up to The change affects 2 systems. Changed systems: Architecture concerns Review detailsSystems and components
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🚥 Pre-merge checks | ✅ 4 | ❌ 1❌ Failed checks (1 warning)
✅ Passed checks (4 passed)
Full details: Docstring CoverageExplanation Docstring coverage is 22.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 50 functions across 9 files. (1 skipped: 1 unsupported.)
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`-warn-long-function-bodies=100` on the simulator build named nine bodies between 0.2 and 1.1 s (M5, one slice): ChatView.body 1.1 s, GitPRDiffCardView.body 0.75, AgentThoughtChamberView.expandedContent 0.71, ActivityRunChip.body 0.59, AgentProfileView.body 0.51, NewSectionSheet.botCell 0.34, CredentialRequestCardView.body 0.30, RoutineEditorView.body 0.28, PredictiveActionChipsView.body 0.22. Each was one expression: a stack of sections, rows, colour ternaries and multi-statement closures the solver searched as a whole. Each is now the same view tree in named pieces: a section, a row or a pill is its own property or function; a closure body of more than one line is a method; a colour chosen by a ternary is a typed `let` or property. No literal moved out of its Text/Label/Button call, so the localisation keys are unchanged, and no view gained or lost state. After: the slowest of the nine is ChatView.body at 0.14 s, and the slowest body in the app is DigestSheet.body at 0.21 s. These were not the cause of the 25-minute CI build (that was IRGen on the @ViewBuilder shims, the previous commit); they are what the type-check limit the next commit adds would otherwise trip on. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
ios/project.yml (Debug) passes -warn-long-expression-type-checking=500 and -warn-long-function-bodies=500, so Xcode shows a slow body as a warning at its line, and the CI step after the simulator build reads those warnings out of the build log and fails with the file:line. Swift 6.3 has no diagnostic group for these two warnings (-Werror <group> answers "unknown warning group"), so the log is read rather than the compiler asked to make only them errors. timeout-minutes 30 → 15: the job is about five minutes (tests ~1.5, xcodegen ~1, build ~2 on the runner), and the old cap is what let a 5× regression read as "cancelled" for a day. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
milind-soni
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Their bodies type-check in 263 ms and 216 ms on an M5 (main's code, limit set to 100 ms); at the runner's 1.2–1.6× that is at most 421 ms and 346 ms, under the 500 ms guard with margin. The split bought no CI time and put ~400 changed lines into two files other iOS PRs touch daily. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
The incident class the type-check guard cannot see: a @ViewBuilder View extension branching on #available doubles the caller's view type at every call, and IRGen on the batch holding both ran until the job cap. A build killed at the cap prints nothing, so the rule is checked at the source, before the build: scripts/check-ios-view-shims.sh fails with file:line on any `#available(` inside an `extension View { … }` block. The two widget background helpers were the last of that shape; they are one ViewModifier now, so there is no allow-list. Drop -showBuildTimingSummary: it prints only after a finished build (so never for the case it was meant for) and gives per-task-type totals, not the slow batch; the guard steps name the file:line instead. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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Review comments at @scripts/check-ios-view-shims.sh:
- Around line 26-28: Update the brace-depth tracking in the AWK logic to ignore
braces inside Swift string and comment contents, so a brace in a property value
cannot end tracking of the `extension View` early. Apply this within the
`opens`, `closes`, and `depth` logic while preserving the existing shim
detection behavior.
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📒 Files selected for processing (11)
.github/workflows/ci.ymlios/App/ActivityRunChip.swiftios/App/AgentProfileView.swiftios/App/BackDeployCompat.swiftios/App/Cards/AgentThoughtChamberView.swiftios/App/Cards/GitPRDiffCardView.swiftios/App/ChatView.swiftios/App/NewSectionSheet.swiftios/Widgets/UpdatesSnapshotProvider.swiftios/project.ymlscripts/check-ios-view-shims.sh
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- ios/App/BackDeployCompat.swift
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…gs; ignore braces in strings The guard step failed on 60766d9 (run 37172158801) with no Swift change from the green runs: RoutineEditorView.body 600 ms and PredictiveActionChipsView.body 551 ms, the two bodies kept as on main at review. They measure 263 and 216 ms on an M5 and were under 420 ms on the calibration run; this runner was 2.3x the M5. The compiler reports wall-clock time, and the shared 3-core runner swings about 2x run to run, so 500 ms is a developer-Mac bar, not a CI verdict. ios/project.yml keeps the 500 ms warning (Xcode shows it at the line). The CI step now prints every body over that limit and fails only on one over 1500 ms, three times the bar: no body in the app comes near it, and a type-check problem on its way to a timeout runs past it. The ms is parsed from the warning text with awk; checked against the real log (551/600 pass and are listed), a synthetic 1600 (fails), 1500/1501 (pass/fail), and an empty log (pass). scripts/check-ios-view-shims.sh: string literals are blanked before the line-comment strip and the brace count, so `var brace: String { "}" }` inside an `extension View` no longer closes the block early and hides a later #available (CodeRabbit on d8a90a1). Mutation-tested: the old script passed that file, the new one fails it at its line; the plain shim shape still fails; braces and // inside strings alone still pass. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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Problem
"Swift tests + iOS build" took 4.9–7 min on every main run up to b455e0f (07:57 UTC Oct 3), 26.4 min on 4302a9c (run 37142024724), and was killed at the 30-minute cap on c2fc677 and a0679ea (runs 37149737054, 37160326719). A killed job marks main's run "cancelled", which hid main's verdict for a day. Same runner image and Xcode 26.6 (17F113) throughout; the code was the variable.
Cause: IRGen on the iOS 16 shims, not a slow expression
The compile batch "ActivityRunChip … CompactRoster" (22 files) stalled. Reproduced locally by forcing CI's batching (
-driver-batch-count 4, the 3-core runner's shape): that one frontend ran until killed while every other batch finished in ~10 s.sampleof the stuck process is IRGen —IRGenSILFunction::emitSILFunction → … → MultiPayloadEnumImplStrategy::destroy → forNontrivialPayloads → …forty frames deep, emitting the outlined destroy of one enormous view type.The iOS 16 shims in
ios/App/BackDeployCompat.swiftwere@ViewBuilderView extensions branching on#available, so each call returned a_ConditionalContentwhose payloads each wrap the whole view it was applied to:onValueChange(3 branches) tripled the caller's type, the rest doubled it.ChatView.bodychains 19 of them (16 at b455e0f; d7e5463 #2208 added 3) — ~3¹⁹ the size. IRGen only meets that type when the shim file and the caller are primaries of the same batch: a 10-core Mac makes 10 batches and never pairs them (local builds always 27–38 s); the 3-core runner makes 4 batches of 22 and batch one holds both. The "fast" runs already carried a 3m41s gap on this batch (3¹⁶); 16 → 19 calls made it 25 minutes.The
-warn-long-function-bodieswarnings (nine bodies at 0.2–1.1 s) predate the regression and were not it — but they are the usual way a SwiftUI build turns into a timeout, and the guard below trips on them, so the ones at or near the limit are fixed too.What changed
BackDeployCompat.swift: every#availableshim is aViewModifierthat branches over its placeholder content, so a call wraps the view once and the type grows linearly with the chain. Call sites unchanged (61onValueChange, 3feedback, 2 eachscrollAnchorCompat/rowSelectionDisabled/pulseCompat, 1 eachsheetChromeCompat/scrollClipDisabledCompat/onValueChangePair). The header comment states the rule.ci.yml:ARCHS=arm64(and-showBuildTimingSummary, dropped again in d8a90a1).let. Same view tree, same state, no literal moved out of itsText/Label/Buttoncall (localisation keys unchanged). Nine bodies here; two restored in 8f22545.ios/project.yml(Debug):-Xfrontend -warn-long-expression-type-checking=500 -Xfrontend -warn-long-function-bodies=500, so Xcode shows a slow body as a warning at its line.ci.yml: the step after the build reads those warnings out of the build log and fails with the file:line.timeout-minutes30 → 15.TasksRoutinesView.swiftandPredictiveActionChipsView.swiftback to main's versions (review).scripts/check-ios-view-shims.sh+ a CI step before the build: fails with file:line on any#available(inside anextension View { … }block — the mechanical form of the rule from abf41ce, for the IRGen class the type-check flag cannot see.ios/Widgets/UpdatesSnapshotProvider.swift: the two widget background helpers (the last of the old shape) are oneViewModifier, so the check has no allow-list.-showBuildTimingSummarydropped (review).Why grep and not
-warnings-as-errors: Swift 6.3 has no diagnostic group for these two warnings (-Werror debug_long_expressionanswersunknown warning group), and plain-warnings-as-errorswould promote every warning. Checked withswiftc -print-diagnostic-groups: the warning prints with no[#Group]tag.One architecture: the
generic/platform=iOS Simulatordestination builds arm64 and x86_64 (16 + 16 SwiftCompile tasks in CI's own logs and locally), andONLY_ACTIVE_ARCH=YESis a no-op with a generic destination (tested: still 16 + 16). Nothing runs the x86_64 slice — the runner, the UI-test simulators and every current Mac are arm64 — soARCHS=arm64builds the one that is used. Two slices also ran six swift-frontends side by side on a 3-core, 7 GB runner.Two guards, one per failure class.
check-ios-view-shims.sh(before the build, ~1 s) catches the view-type blow-up at the source; the type-check step (after the build) catches a slow constraint problem at its line. Both end as a red step with a file:line.timeout-minutes: 15is left as the hang guard only.Type-check time per body (M5, one slice,
-warn-long-function-bodies=100)ChatView.body(ChatView.swift:173)GitPRDiffCardView.bodyAgentThoughtChamberView.expandedContentActivityRunChip.bodyAgentProfileView.bodyNewSectionSheet.botCellCredentialRequestCardView.body(ChatView.swift)RoutineEditorView.body263 ms (main's code, unchanged)Left as on main:
RoutineEditorView.body(TasksRoutinesView.swift:246) 263 ms andPredictiveActionChipsView.body(:44) 216 ms — at the runner's 1.2–1.6× that is ≤ 421 ms and ≤ 346 ms, under the 500 ms guard with margin (see Review fixes). Next after those:DigestSheet.body167 ms,ComputerView.body153 ms.Runner calibration (throwaway run 37168687102, job 111337635883, limit set to 100 ms so every body over 100 ms is listed): the slowest bodies on the 3-core
macos-latestrunner wereComputerView.body247 ms,DigestSheet.body246 ms,ChatView.composer190 ms,TeamMemoryView.body173 ms,TextBubble.body165 ms,CardView.body163 ms,QuickReplyForm.body154 ms,ChatView.body149 ms — 19 bodies over 100 ms, none over 250. The runner is about 1.2–1.6× the M5 here. That run also shows the guard doing its job: the type-check step failed with the 19file:lineentries and a::error::annotation while the build itself still took 68 s.Build time
Local, M5 (10 cores), Xcode 26.6, clean derived data each time, wall clock of the xcodebuild step:
-driver-batch-count 4(the 3-core runner's batching)-driver-batch-count 4CI (
macos-latest, 3 vCPU), the "Build the simulator app" step:Swift package tests: 888 tests before and after (
swift test --package-path ios, 0 failures); on CI 58 s. Whole job at ea380f7: 2 min 13 s (checkout 5 s, package tests 58 s, xcodegen 5 s, build 63 s, type-check step < 1 s). The 15-minute cap is a hang guard, not room for the build to grow into.Review fixes
Three findings on the PR, all applied:
scripts/check-ios-view-shims.shruns before the build and fails with file:line on any#available(inside anextension View { … }block; the two widget helpers atUpdatesSnapshotProvider.swift:153,167are oneViewModifiernow, so there is no allow-list. The rule is scoped to the extension block rather than "@ViewBuilderfollowed by#available" because the latter needs a proximity window andEmptyStateViewhas a@ViewBuilder var actionsthree lines above abodythat legitimately branches on#available(a leaf view, not a wrapper) — the extension scope is the rule exactly as the BackDeployCompat header states it, and aViewModifiercan never trip it. Mutation-tested: re-adding one@ViewBuilder func xCompat() -> some View { if #available … self }to BackDeployCompat.swift fails the step at its line; the unconverted widget file failed it at :155 and :168. Option (b), a CPU-second budget read from the timing summary, was not taken: it needs a finished build to print anything and a number that drifts with the app and the runner.-showBuildTimingSummarywas a leftover flag whose rationale does not hold. Dropped, with its comment lines;ARCHS=arm64,set -o pipefailand theteestay for the type-check step.RoutineEditorView.bodyandPredictiveActionChipsView.bodywere refactored though they could never fail the guard. Restored to main's versions in 8f22545 (a new commit rather than an amend of 25b2c29: the branch was already pushed and is not force-pushed). Re-measured on main's code at the 100 ms limit: 263 ms and 216 ms on the M5, ≤ 421 / 346 ms at the runner's 1.6×. The five bodies over 500 ms and the two within 1.6× of it (CredentialRequestCardView.body299 → ≥ 479 ms,NewSectionSheet.botCell342 → ≥ 547 ms) keep their splits.Verified
swift test --package-path ios: 888 tests, 0 failures, before and after (re-run at d8a90a1).ARCHS=arm64, no timing flag): BUILD SUCCEEDED in 21 s, 0 x86_64 SwiftCompile tasks, the-warn-long-*=500flags on all 9 swiftc lines, the type-check grep finds no hit; the three warnings in the log are main's (LocalVmControlView.swift:343,LocalVmDesktop.swift:134, AppIntents metadata).bash scripts/check-ios-view-shims.sh: passes on the tree; fails with file:line on the old widget file and on a re-added builder shim (above).pnpm exec vitest run scripts/ci-workflow.test.ts scripts/ci-scope.test.ts: 53 passed against the edited workflow.Not done / notes
scripts/check-ios-view-shims.shreadsextension Viewblocks. A generic containerViewwhosebodybranches on#availableover itsContent(the shape ofGlassGroup) would double in the same way if chained; none is, and nothing in the app chains one.pnpm typecheckon main's ownChatView.tsx(950,45): Cannot find name 'bot'(d6f3dfc Live frames carry no screenshot pixels; the desktop loads screenshots by URL #2259); main fixed that in fix(chat): screen rows read threadId from the rows context — unblocks main's typecheck #2272 (6b5810b).tmp/ios-typecheck-calibrationbranch (limit at 100 ms, one commit on ea380f7) was pushed only to read the runner's numbers above and is deleted.Platforms
ios/App)ViewModifierViewModifier(call sites unchanged)Swift tests + iOS buildonly: one new step, one flag removed🤖 Generated with Claude Code
Summary by CodeRabbit
Refactor
Chores
Two more after main was merged in (60766d9, no Swift change on main since the merge-base):
RoutineEditorView.body600 ms andPredictiveActionChipsView.body551 ms — the two bodies kept as on main at review, 263/216 ms on the M5 and ≤ 420 ms on the calibration run; this runner was 2.3× the M5. The compiler reports wall-clock time, and the shared 3-core runner swings about 2× from one run to the next, so 500 ms is a developer-Mac bar, not a CI verdict. b71924e:ios/project.ymlkeeps the 500 ms warning (Xcode shows it at the line); the CI step lists every body over it and fails only on one over 1500 ms — three times the bar, which no body in the app comes near and which a type-check problem on its way to a timeout runs past. The green run that followed (37173797613) listedRoutineEditorView.bodyat 505 ms and passed; at a 500 ms bar it would have been a second red run on unchanged code. The step's awk was checked against the real log (551/600 → listed, pass), a synthetic 1600 (fail), 1500/1501 (pass/fail) and an empty log (pass).}inside a string literal in anextension Viewblock closed the block early, so a later#available(in it passedscripts/check-ios-view-shims.sh. String literals are blanked before the line-comment strip and the brace count (b71924e). Mutation-tested: the old script passed a file withvar brace: String { "}" }followed by a@ViewBuilder#availableshim; the new one fails it at its line; the plain shim shape still fails; braces and//inside strings alone still pass.