--- title: Uber open-sources a speculative merge queue, Chrome... description: Uber released SubmitQueue, a Go-based speculative merge queue that validates multiple changes in parallel against predicted future HEAD states to keep trunk... canonical: https://daily.dev/posts/uber-open-sources-a-speculative-merge-queue-chrome-lands-on-arm64-wflzzg6ki twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Uber open-sources a speculative merge queue, Chrome lands on arm64 | daily.dev og:description: Uber released SubmitQueue, a Go-based speculative merge queue that validates multiple changes in parallel against predicted future HEAD states to keep trunk... og:url: https://daily.dev/posts/uber-open-sources-a-speculative-merge-queue-chrome-lands-on-arm64-wflzzg6ki og:image: https://api.daily.dev/og/posts/WFLzzG6kI.png og:image:alt: Uber open-sources a speculative merge queue, Chrome lands on arm64 og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Uber open-sources a speculative merge queue, Chrome lands on arm64 **[Testing Digest](https://daily.dev/sources/testing_digest)** · 4 min read · 0 upvotes · 0 comments ## Summary Uber released SubmitQueue, a Go-based speculative merge queue that validates multiple changes in parallel against predicted future HEAD states to keep trunk green at scale. Chrome shipped official arm64 Linux builds on July 30, cutting energy use by up to 60% and cost by up to 20% for teams running browser automation on Graviton. Microsoft's .NET test agent was already covered last week, but Pest 5's TIA and agent features got a fresh practical demo this week. SQLite's Richard Hipp detailed the test methodology behind its legendary reliability: a suite 6.5x larger than the codebase itself, 100% MCDC coverage, and fault injection that nearly eliminated bug reports after 2009. ## Content **TLDR:** Uber released SubmitQueue, a Go-based speculative merge queue that validates multiple changes in parallel against predicted future HEAD states to keep trunk green at scale. Chrome shipped official arm64 Linux builds on July 30, cutting energy use by up to 60% and cost by up to 20% for teams running browser automation on Graviton. Microsoft's .NET test agent was already covered last week, but Pest 5's TIA and agent features got a fresh practical demo this week. SQLite's Richard Hipp detailed the test methodology behind its legendary reliability: a suite 6.5x larger than the codebase itself, 100% MCDC coverage, and fault injection that nearly eliminated bug reports after 2009. --- ## Uber open-sources SubmitQueue, a speculative merge queue for keeping trunk green Rather than validating PRs sequentially, SubmitQueue speculatively rebases and validates multiple changes in parallel against predicted future HEAD states. When a validation fails, it isolates the offending change and retries the rest automatically — no human intervention needed. The repo includes a Gateway, Orchestrator, and MySQL backend, runnable locally via Docker Compose. If you're running a large monorepo with frequent concurrent merges and flaky-trunk problems, this is worth a look. [Read more](https://daily.dev/posts/kbreev4b8) ## Chrome ships official arm64 Linux builds, enabling cheaper CI on Graviton As of July 30, 2026, Google's arm64 .deb and .rpm packages are available via the standard Chrome download page and apt/RPM repos. For teams running Playwright or Cypress at scale, this means arm64 instances — which use up to 60% less energy and cost up to 20% less than comparable x86 — are now a viable CI target. Chrome for Testing arm64 builds are also confirmed in progress, which is the piece that matters most for headless automation pipelines. [Read more](https://daily.dev/posts/0eDrCD58W) ## SQLite's test suite is 6.5x larger than the codebase, and that's the point Richard Hipp walked through the engineering behind SQLite's reliability at SSW 2026. The test suite runs 14.5 million cases and targets 100% MCDC (Modified Condition/Decision Coverage), a standard borrowed from aviation's DO-178B. Achieving that threshold in 2009 nearly eliminated bug reports and unlocked a 3x performance improvement — because you can safely micro-optimize when you trust the tests. Fault injection runs through pluggable VFS and memory allocator interfaces, and crash simulation covers power-loss scenarios for ACID correctness. The core lesson: design for testability from day one, and don't treat a large test codebase as a liability. [Read more](https://daily.dev/posts/dpU0PabhT) ## Coding agent evals need executable contracts, not exact-match grading Two posts this week converge on the same point from different angles. The first argues that coding agents should be evaluated as full systems — model, harness, tools, context, environment — using contracts like build success, passing tests, API compatibility, and security checks, with non-determinism handled statistically across multiple runs. The second is a junior engineer's postmortem of an AI support-routing agent that broke within three days because the team had observability but no evals: only 52% of teams run offline evals per LangChain survey data. Together they make a practical case for treating eval coverage as seriously as test coverage. [Read more](https://daily.dev/feed-by-ids?id=uLsExxNuX&id=PQ4Qs5n7V) --- ## Also notable - **Node.js 26.7.0 adds --test-coverage-include-all flag and Perfetto tracing:** The test runner gains --test-coverage-include-all in 26.7.0, and Perfetto tracing support lands for improved diagnostics — both worth knowing if you're on the Node.js 26 Current track. [Read more](https://daily.dev/feed-by-ids?id=qxmBCssFW&id=C9pcB85v8&id=qWDptySuw) - **PHPUnit 12.5 requires distinguishing mocks from stubs, Rector can automate the migration:** PHPUnit 12.5 enforces stricter mock handling — createMock() now requires expectations, and stubs need createStub() — with Rector's phpunitCodeQuality set automating most of the seven concrete diffs needed to upgrade. [Read more](https://daily.dev/posts/wamTyjGxT) - **LitmusChaos shipped CVE-2026-33186 patch and grew to 279 contributors in H1 2026:** Six releases (3.25.0–3.30.0) landed in H1 2026, including a CVE patch, Prometheus metrics, and a new MCP integration for natural-language chaos experiment interaction; Canonical joined as an official adopter. [Read more](https://daily.dev/posts/ob3RCTFyw) - **time-machine is 27,300x faster than freezegun at 16,000 modules:** The difference is architectural: freezegun scans all sys.modules to rebind references (O(n)), while time-machine overwrites C function pointers directly (O(1)) — a migration CLI is available to automate the switch. [Read more](https://daily.dev/posts/9Nqxc2zKE) - **Bun's next release adds timing-aware CI sharding with longest-processing-time-first scheduling:** bun test --timings records per-file durations, and bun test --parallel --shard=i/N uses those timings to distribute work across CI runners optimally rather than splitting files naively. [Read more](https://daily.dev/posts/UGgFjvZta) ## Similar posts on daily.dev - [GitHub - uber/submitqueue: SubmitQueue is a high-performance speculative merge queue that keeps your trunk consistently green at scale.](https://daily.dev/posts/github---uber-submitqueue-submitqueue-is-a-high-performance-speculative-merge-queue-that-keeps-your-kbreev4b8) · Hacker News · 23 upvotes · 1 comments - [Chrome lands on arm64](https://daily.dev/posts/chrome-lands-on-arm64-0edrcd58w) · Calibre · 5 upvotes · 0 comments --- Tags: [#testing](https://daily.dev/tags/testing), [#cicd](https://daily.dev/tags/cicd), [#google-chrome](https://daily.dev/tags/google-chrome), [#sqlite](https://daily.dev/tags/sqlite) [View this post on daily.dev](https://daily.dev/posts/uber-open-sources-a-speculative-merge-queue-chrome-lands-on-arm64-wflzzg6ki) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"DiscussionForumPosting","mainEntityOfPage":"https://daily.dev/posts/uber-open-sources-a-speculative-merge-queue-chrome-lands-on-arm64-wflzzg6ki","headline":"Uber open-sources a speculative merge queue, Chrome lands on arm64","text":"Uber released SubmitQueue, a Go-based speculative merge queue that validates multiple changes in parallel against predicted future HEAD states to keep trunk green at scale. 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