Function infer_with_report 

pub fn infer_with_report(
    samples: &[Doc],
    root_name: &str,
    allow_any: bool,
) -> Result<(Schema, Vec<AnyFallback>), SchemaError>

Like infer, but also takes allow_any and returns every AnyFallback recorded along the way (empty when allow_any is false, since every ambiguous field is a hard error in that mode instead). Mirrors Python’s infer_with_report.