Editing Openai/691a14bb-ac48-8008-85d0-2e4fb3f780d1 (section)

=== Assistant: If GPT-5 High Reasoning has looped for hours without progress, stop using it for this bug. ===
If GPT-5 High Reasoning has looped for hours without progress, stop using it for this bug. The model is optimized for planning and large-context reasoning, not for breaking causal deadlocks in already-attempted code paths.

Switch model based on the type of failure:

| Symptom                                                                | Recommended model        | Reason                                                                                 |
| ---------------------------------------------------------------------- | ------------------------ | -------------------------------------------------------------------------------------- |
| Complex but localized runtime error (stack trace, nulls, DB, or logic) | Claude Opus 4.1 Thinking | Excels at tracing execution flow and identifying where assumptions fail.               |
| Multi-file interaction or config mismatch                              | Kimi K2                  | Very large context window lets it see the entire subsystem and correlate dependencies. |
| Bug linked to commit history, structure, or code hygiene               | SWE-1.5                  | Designed for Windsurf repos; good at diff analysis and fix commits.                    |
| Network, HTTP, or API-integration errors                               | Gemini 2.5 Pro           | Strong reasoning on request/response and schema mismatches.                            |
| Subtle logical or state-invariant bug                                  | o3 High Reasoning        | Stepwise formal logic avoids repetitive speculation.                                   |
| Need to generate failing tests to isolate cause                        | Qwen3-Coder Fast         | Produces concise reproducible test cases quickly.                                      |

Recommended next step:
Use Claude Opus 4.1 Thinking to re-analyze the failure with this directive:

<syntaxhighlight>Goal: Identify exact root cause and fix for [describe failure].

Constraints:
* Produce a new hypothesis tree—no repetition of prior GPT-5 attempts.
* At each branch, state what evidence would confirm or falsify it.
* Stop after finding first falsifiable root cause; then generate a single verified patch and test.

</syntaxhighlight>

If that model converges, let SWE-1.5 apply and validate the patch within your repo.