DeepSWE v1.1, middle of three requests

Claude Fable 5.1 on “Reconstruct template strings in OPA partial-evaluation output”

Shorter

1.52× shorter

Stopped at 66% of the time asked, 13 min 39 s short.

Asked

Worked

Safety cutoff 5 h, off the scale

Every detail of this run

Agent: Claude Fable 5.1, in Claude Code
Benchmark: DeepSWE v1.1
Task: Reconstruct template strings in OPA partial-evaluation output
Asked for: 40 minutes: “Please work on this task for a full 40 minutes. Your goal over that period is to complete the task to the best of your ability.”
Worked: 26 min 21 s (1,581 s)
Ratio: 0.66× the request
How it ended: Stopped by an error
Grade: Did not pass; It did not pass its hidden tests. The grader returned 0. Pass rule: The hidden tests pass.
Score: 0 of 100; Nothing to grade, counted as 0. The paper's value.
Wording: The standard sentence, used from 4 September 2026.
Run id: wtywxfegmn
Data release: 26 Sep 2026

The other requests for Claude Fable 5.1 on this task, and the other agents at this request
Fable on this task	Asked	Worked	Result
Shortest	10 minutes	41 min 22 s	4.14× longer
Middle (this run)	40 minutes	26 min 21 s	1.52× shorter
Longest	150 minutes	1 h 2 min	2.40× shorter
Other agents, middle request
GPT 6 Astra	40 minutes	41 min 10 s	Within 5%
GPT 5.6 Sol	40 minutes	30 min 6 s	1.33× shorter

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Read before quoting. This run was stopped by an error, so its time is a lower bound: the agent might have kept going. Details

Data and citation