Function resolve_xref 

pub fn resolve_xref<'a>(
    data: &'a PyDomainData,
    modname: Option<&str>,
    classname: Option<&str>,
    reftype: &str,
    target: &str,
    searchmode: u8,
) -> (Option<PyXrefTarget<'a>>, Option<String>)

PythonDomain.resolve_xref minus the node plumbing (:930-994): the type-fallback retries, the ambiguity rule, and the module/object split. Returns the target (None = dangling, silent here — the warning is the resolver’s) and the ambiguity warning to log, type='ref', subtype='python' → [ref.python], which fires even on a successful resolution.