[leehack]

Summary

• Pin leehack/[email protected] (owner PR #119, merge 5da99205; release), which stops shipping the macOS libLiteRt.dylib and libLiteRtWebGpuAccelerator.dylib and the iOS loose libLiteRt.dylib. LiteRtLm embeds LiteRT and its GPU accelerator, so dyld traces show none of them is opened.
• Companion Package.swift drops the LiteRt and LiteRtWebGpuAccelerator targets (4 binary targets left); the v0.19 macOS required-library inventory, the prepare-app script and the sync script follow. The sync remover matches name: "LiteRt" exactly and refuses a release that drops only one of the two.
• Admits v0.19.1-4 in the LiteRT-LM library smoke and the S24 binding (Android archives hold the same libraries as v0.19.1-3).
• Fixes #1911.

Production-readiness scope

• User-facing scope: macOS LiteRT-LM apps drop two dylibs (16.9 MB installed; 6.2 MB less XCFramework download via llamadart_litert_lm_flutter, same for the hook bundle); iOS hook download drops 2.7 MB per slice. Generation unchanged.
• Supported platforms/paths: macOS arm64 hook and SwiftPM companion, iOS hook; Android, Linux and Windows unchanged.
• Unsupported or intentionally unavailable paths: v0.18.x and earlier owner releases keep their inventories (sync tests cover both).
• Out of scope / follow-ups: iOS loose libLiteRtLm.dylib and the WebgpuDawn target left in place; each is a possible follow-up. Overlap with Name the pinned LiteRT-LM runtime tag in unsupported-runtime errors #1920 is resolved (rebased on e632b443, which includes 0.19.6 batch integration: #1920, #1922, #1919, #1924 #1926).

Completeness checklist

• Scope implemented
• Unsupported combinations: N/A (inventory reduction)
• Docs, README, skills, changelogs updated
• Regression coverage incl. version-skew (v0.18 keeps files)
• Validation registry: N/A, no capability change
• Security/privacy: no secrets in logs or evidence

PR type guidance

• Feature PR: N/A. Bugfix PR: N/A. Packaging change: root cause is the unused libraries, evidence in #1911.

Test Plan

• dart run tool/prepare_workspace.dart
• dart format --output=none --set-exit-if-changed .
• dart analyze
• dart test -p vm -j 1 --exclude-tags local-only (TMPDIR isolated): all pass except 6 windows_registry_qualification_test.dart cases that need pwsh, absent on this Mac (CI covers)
• dart test -p chrome --exclude-tags local-only: CI
• coverage-lib: CI/main; lib/ change is list removals
• python3 -m unittest discover -s tool/native -p 'test_*.py' (207), check_native_release_digests.dart (8 LiteRT-LM bundles match v0.19.1-4), companion and validation package tests
• Mutants caught: re-adding libLiteRt.dylib to _liteRtLmV1RequiredLibrariesForAbi; Swift remover dropping one target; substring instead of exact name: "LiteRt" match

Matrix Evidence

Matrix row	Scope covered	Platform / model / backend	Result	Evidence / notes
litert-lm-chat-features-smoke	chat features	macOS, Qwen3-0.6B, CPU and GPU, hook at v0.19.1-4	pass	hook dir holds 4 dylibs
litert-lm-json-schema	JSON Schema	macOS, Gemma 4 E2B, CPU and GPU	pass
litert-lm-multimodal-embedding	embeddings	macOS, EmbeddingGemma 2, CPU	pass
litert-lm-asr-smoke	ASR	macOS, Moonshine tiny	pass	transcript matched
chat app macOS build	companion layout	flutter build macos --debug	pass	otool -L: LiteRtLm.framework depends only on its Gemma provider and Dawn; no LiteRt or accelerator embedded
iOS simulator probe	C ABI	iOS 26.5 sim, Qwen3-0.6B CPU and GPU, released arm64-sim LiteRtLm (same bytes as PR candidate)	pass	simctl spawn of the C probe; no T3 device session
Gemma 4 vision/audio/MTP, GPU	media	macOS	covered by pre-adoption evidence with the libraries deleted (#1911); not rerun at the pin

Review Notes

• Independent review status: PASS at e11d7997 (fresh auditor session, 0 P1/P2): digests and SwiftPM checksums match v0.19.1-4; sandboxed macOS chat app and iOS 26.5 simulator JSON Schema on GPU pass through the trimmed companion; v0.19.1-3 override passes; Windows DLL diff is build metadata only; evaluator exit 2. Evidence: llamadart-evidence/pr-1927/
• CI status / head SHA: green (37 pass, 9 skipped) at e11d7997

High-risk regression review

• Classification: high-risk (artifactConsumer, backendRuntime)
• Implementation task: lane-1911
• Independent blocking QA task: PASS at e11d7997, 0 P1/P2. Maintainer merge approval given ("Merge Drop the unused LiteRT and WebGPU accelerator libraries from Apple bundles (#1911) #1927"). Audit P3s are logged on 0.19.x audit follow-ups (index) #1861.
• Exact head / current base: e11d7997 / e632b443
• Production-branch deletion, bypass, or miswire proof: hook cache at v0.19.1-4 holds exactly the four required dylibs and the e2e rows above load them; mutants above fail the inventory tests
• Affected-family real-model/artifact evidence: table above
• Explicit unavailable-family or other N/A evidence: Gemma 4 media/MTP and iOS app-level run not rerun at the pin
• Known PR-caused P1 regressions: 0
• Unresolved review threads: 0

[github-actions]

Chat app preview removed for leehack/llamadart-chat-pr-1927.