mbed-os/tools/test/config/double_define/test_data.json

{
    "double_config": {
        "exception_msg": "Parameter name 'base1_1' defined in both 'target:second_base' and 'target:first_base'"
    },
    "second_base": {
        "target.base2_1": "v_base2_1_b2",
        "target.base2_2": "v_base2_2_b2",
        "target.base1_1": "v_base1_1_b2"
    }
}