{
  "hub_commit": "ede75c00118e9808e5099da43c26f4619cc3bc37",
  "case": {
    "id": "ekf-covariance",
    "title": "EKF covariance must be symmetric positive definite",
    "resolution": "A zero/negative initial covariance eigenvalue violates this adapter precondition. The valid example uses a positive diagonal covariance; choose values justified by the actual model.",
    "mode": "input",
    "skill_id": "pythonrobotics-ekf-update",
    "bad_skill_id": "pythonrobotics-ekf-update",
    "runtime": "pythonrobotics",
    "source_commit": "cdd0cc888802b584c2d654ca85e3c5460973487d",
    "bad_input": {
      "state": [
        0,
        0,
        0,
        1
      ],
      "covariance": [
        [
          -0.1,
          0.0,
          0.0,
          0.0
        ],
        [
          0.0,
          0.1,
          0.0,
          0.0
        ],
        [
          0.0,
          0.0,
          0.1,
          0.0
        ],
        [
          0.0,
          0.0,
          0.0,
          0.1
        ]
      ],
      "measurement_xy": [
        0.15,
        0.02
      ],
      "control_v_yawrate": [
        1,
        0.1
      ]
    },
    "good_input": {
      "state": [
        0,
        0,
        0,
        1
      ],
      "covariance": [
        [
          0.1,
          0.0,
          0.0,
          0.0
        ],
        [
          0.0,
          0.1,
          0.0,
          0.0
        ],
        [
          0.0,
          0.0,
          0.1,
          0.0
        ],
        [
          0.0,
          0.0,
          0.0,
          0.1
        ]
      ],
      "measurement_xy": [
        0.15,
        0.02
      ],
      "control_v_yawrate": [
        1,
        0.1
      ]
    },
    "contracts_sha256": "a48749d4a521ccaff23f84c626c8a86195a0bb2e02b8fc4fb681a6e8ac565c6a",
    "scope": "Authored reproduction; not autonomous agent discovery, general accuracy or hardware verification."
  },
  "evidence": {
    "id": "ekf-covariance",
    "case_sha256": "b44c4105878bfd58a19384efd81e28e38934f1b15352f8a8e4b49fea2a0e6205",
    "problem_reproduced": true,
    "valid_case_passed": true,
    "observed_problem": {
      "exit_code": 2,
      "reason_code": "invalid_input_or_environment"
    },
    "checks": {
      "finite_state": true,
      "symmetric_covariance": true,
      "positive_semidefinite_covariance": true
    },
    "adapter_sha256": "1aad261b6b6309ea716a19ae709631901cff315fcb430b19f295942f9ea36bd9",
    "bad_adapter_sha256": "1aad261b6b6309ea716a19ae709631901cff315fcb430b19f295942f9ea36bd9",
    "source_commit": "cdd0cc888802b584c2d654ca85e3c5460973487d",
    "mode": "input"
  },
  "observed_at": "2026-10-20T04:15:40.176754+00:00",
  "maintainer_authored": true
}