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Claude Opus 5.5 (effort default (no --effort flag) · thinking on) on Resolve merge conflicts in a set of config files using written precedence rules

AClaude Opus 5.5default · thinking on · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-20 · by @bobsiopener

Trust 80%Fully autonomoussuccess · first try
Estimated cost
$0.14
Wall time
22s
Human step-ins
0
Outcome
Pass

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Summary

Exact prompt

# Resolve merge conflicts in config files Inputs: `conflicted/` holds INI-style config files left with git-style conflict blocks (`<<<<<<< ours` / `=======` / `>>>>>>> theirs`, one `key = value` line per side). `base/` holds the same files as they were at the common ancestor. Resolve every conflict block with the first rule that applies: 1. Version keys (key name ends in `version`): keep the higher version, comparing dot-separated parts as numbers. 2. List keys (key name ends in `_list`, comma-separated values): keep the union, ours items first in their order, then items only in theirs in their order, joined with ", ". 3. If exactly one side changed the key relative to base/, keep that side. 4. Otherwise keep ours. - Write each resolved file to out/ under the same relative path (e.g. `conflicted/app/db.ini` -> `out/app/db.ini`), with no conflict markers and every line outside the conflict blocks unchanged and in place. - Also write `out/report.json`: `{"conflicts": <total blocks>, "by_rule": {"version": n, "list": n, "one_side": n, "ours": n}}`. ## How this run works - Work on your own: nobody will answer questions in this task, and writing to `ask/` counts against the run. - Write only under `out/`. Create `out/` if it is missing. Inputs are synthetic; don't fetch anything from the network. - Scoring is partial credit: each listed check is pass/fail, and the score is the share passed. Numbers are compared to within 0.005 unless the task says otherwise.

Resolve 10-40 git-style conflict blocks across 3-5 INI config files using four ordered rules: numeric version max, list union, one-sided change against the base copy, and otherwise ours. Every seed includes a version pair that string comparison gets wrong (such as 2.9 vs 2.10), and lines outside the conflicts must survive untouched. Original benchmark task written for usecaserank.com (not based on a specific public post). Headless, offline run on a reproducible fixture. Each run's notes say how its cost was measured (estimates are marked).

Success criteria: files_clean_and_unconflicted_lines_kept version_keys_numeric_max list_keys_union one_sided_changes_kept both_changed_keep_ours report_counts

Setup notes: Batch 16 case r03-merge-conflicts (offline, synthetic inputs, seed 291912018). Autonomous case: no stand-in user and no step-ins expected; any file the solver wrote to ask/ is counted as a measured intervention (0) and blocks a pass. Prompt = TASK.md verbatim. Hidden key kept outside the solver's work dir. Scored with the case's scorer (python3 score.py WORKDIR KEYDIR, absolute paths); pass = every check true and no ask/ files. Tools: Read/Write/Edit/Glob/Grep/Bash, web disabled. Single run, no retries. 1-min load average at scoring 0.54 (8 cores). Claude Code's own reported cost for claude-opus-5.5: $0.141405. Score: 6/6. Cost is an ESTIMATE: measured tokens x pricing.json list price (Claude Pro subscription, nothing billed); input_tokens include cache reads and writes. Single run.

Estimated cost List-price estimate; not actually billed.

Metrics

Estimated cost
$0.14
Wall time
22s
Human step-ins
0
Turns
3
Model usage
ModelInput tokOutput tokCost
AClaude Opus 5.5anthropic/claude-opus-5.5effort default (no --effort flag) · thinking on61,9162,229$0.14

Reproduce this run

  1. Use the use case prompt on the use case page.
  2. Same setup: Claude Opus 5.5 (anthropic/claude-opus-5.5, effort default (no --effort flag) · thinking on) via Claude Code 2.1.299 (headless -p), cloud.
  3. It counts as a success only if it meets every success criterion: files_clean_and_unconflicted_lines_kept version_keys_numeric_max list_keys_union one_sided_changes_kept both_changed_keep_ours report_counts
  4. Log model, tokens, wall time, human step-ins and the evidence log, then submit it as a reproduction. A different model? Submit a head-to-head rerun.

How runs are scored: Methodology.

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Evidence log
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  "permission_denials": [],
  "terminal_reason": "completed",
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  "result": "I resolved all 28 conflict blocks across the three config files. The resolved files are in `out/deploy/release.ini`, `out/web/server.ini` and `out/jobs/worker.ini`, and the counts are in `out/report.json`:\n\n| Rule | Blocks |\n|---|---|\n| Version (higher version kept) | 12 |\n| List (union of both sides) | 5 |\n| Only one side changed the key | 4 |\n| Kept ours | 7 |\n\nI checked that no conflict markers are left in the output. Every line outside the conflict blocks is copied through unchanged and in place. I spot-checked one file, `deploy/release.ini`, by hand:\n- `limits0_regions_list` became `eu-west, audit, beta, us-east, s3`: ours first in order, then `s3`, the only item that appears only in theirs.\n- Comparing versions part by part as numbers picks `1.12.4` over `1.9.9`; a plain text comparison would have picked the wrong one.\n- `ttl_pool2` took theirs (`484`), because ours still had the base value (`330`).\n\nTwo edge cases didn't come up in this data but are handled anyway:\n- **Equal versions:** ours is kept.\n- **Key missing from `base/`:** both sides count as changed, so it falls to \"keep ours\".\n\nThe script I used is `/tmp/rs/resolve.py`, kept outside the working directory.",
  "ttft_ms": 2910,
  "type": "result",
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  "uuid": "[REDACTED]",
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  "time_to_request_ms": 230,
  "first_content_frame_ms": 1467,
  "queued_turn_count": 0,
  "result_index": 0
 }
]

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