Source note3 min read

RuBench: A Repository-Level Agentic Coding Benchmark with Natively Authored Russian Task Specifications

Source

arXiv

arxiv.org/abs/2607.06411v1

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Plain-Language Brief

The author introduces RuBench 1.0, a benchmark for evaluating coding agents that use native language tasks instead of English. The benchmark includes 25 tasks mined from five open-source repositories and is judged by the upstream maintainers' regression tests. The author evaluates several configurations of coding agents and finds that one configuration resolves 78.7% of the tasks.

What the Document Says

  • RuBench 1.0 is a benchmark of 25 tasks in Russian for evaluating product-grade coding agents.
  • The tasks are mined from recent fix commits in five open-source repositories: aiohttp, aiogram, Laravel, NestJS, Fastify (Python, PHP, TypeScript, JavaScript).
  • Each task is specified natively in Russian and judged by the upstream maintainers' regression tests.
  • The author evaluates three independent runs each of Claude Code with Opus 4.8, Sonnet 5, Haiku 4.5, and Codex CLI with GPT-5.5.
  • The best configuration resolves 78.7% of tasks.
  • At N=25, only the gaps to the weakest model are statistically resolvable.
  • The author catches the product silently substituting the model on 5 of 25 tasks.
  • RuBench 1.0 includes task statements, metadata, full agent trajectories, and diffs, but grading oracles are withheld.

Key Concepts Mentioned

  • RuBench
  • coding agents
  • native language tasks
  • upstream maintainers
  • regression tests
  • Claude Code
  • Opus
  • Sonnet
  • Haiku
  • Codex CLI
  • GPT-5.5

Claims Made by the Document

  • The best configuration resolves 78.7% of tasks.
  • At N=25, only the gaps to the weakest model are statistically resolvable.

Evidence Used

  • The author presents evaluation results for several coding agent configurations.
  • The author mentions that at N=25, only the gaps to the weakest model are statistically resolvable.

Methods / Approach

UNKNOWN

Limitations Stated by the Authors

UNKNOWN

Limitations Noted by the Agent

Agent interpretation — not from the source.

UNKNOWN

Open Questions

UNKNOWN

Notes for Future Q&A

May include interpretation. Labeled where it does.

UNKNOWN

Raw Abstract / Excerpt

Developers increasingly delegate real maintenance work to product-grade coding agents, and many state tasks in their native language, in the style of a customer request rather than a curated English issue. Existing repository-level agentic benchmarks do not measure this setting: their task statements are English by design. We introduce RuBench 1.0, a benchmark of 25 tasks mined from recent fix commits in five live open-source repositories (aiohttp, aiogram, Laravel, NestJS, Fastify; Python, PHP, TypeScript, JavaScript), where each task is specified natively in Russian -- written from scratch in the style of an actual customer request, not translated -- and judged by the upstream maintainer's regression tests, which we withhold from release. All 25 fix commits postdate the training-data cutoffs of every evaluated model, giving a contamination argument that holds task-by-task. We evaluate deployed product configurations (CLI agent + model + reasoning effort) -- Claude Code with Opus 4.8, Sonnet 5, and Haiku 4.5, and Codex CLI with GPT-5.5 -- with three independent runs each, reporting pass@1 with task-level confidence intervals, paired comparisons, dollar cost, and token usage. The best configuration resolves 78.7% of tasks; at N=25 only the gaps to the weakest model are statistically resolvable, which we state explicitly. Auditing full trajectories of a fifth, hors-concours configuration (Claude Code + Fable 5, July 2, 2026 release), we caught the product silently substituting the model: on 5 of 25 tasks (20%) an official safeguard fallback re-routed routine HTTP-protocol fixes to Opus 4.8 -- direct, reproducible evidence that the deployed product, not the model, is the unit actually measured. We release task statements, metadata, full agent trajectories, and diffs; grading oracles are withheld, with a SHA-256 manifest committed at publication time.