Debug-Json-Parser-V2

The model receives the prompt (and optional system message). The run uses scorer rubric_json_metrics with the JSON configuration below. Pass/fail and partial credit are determined entirely by that scorer against the model output; no human grading.

Return JSON only with keys diagnosis, fix, tests. A hand-written JSON string parser crashes on escaped quotes and mishandles whitespace after commas. Diagnose the runtime exception and fix strategy.

{
  "metrics": {
    "repro": {
      "checks": [
        {
          "contains": [
            "escaped quote"
          ]
        },
        {
          "contains": [
            "whitespace"
          ]
        },
        {
          "contains": [
            "comma"
          ]
        },
        {
          "contains": [
            "runtime"
          ]
        }
      ]
    },
    "hidden": {
      "checks": [
        {
          "contains": [
            "backslash"
          ]
        },
        {
          "contains": [
            "skip whitespace"
          ]
        },
        {
          "contains": [
            "bounds"
          ]
        }
      ]
    },
    "diagnose": {
      "checks": [
        {
          "contains": [
            "parser"
          ]
        },
        {
          "contains": [
            "string"
          ]
        },
        {
          "contains": [
            "exception"
          ]
        }
      ]
    }
  }
}