Function resolve_logged 

pub async fn resolve_logged(
    input: &str,
    ctx: &ResolveContext,
    source: &dyn CandidateSource,
    picker: &dyn Picker,
    store: &mut dyn BindingStore,
    out: &Output,
    log: &Path,
) -> Result<Resolved>

Resolves input, then appends one line to log (the RCA trail). A log failure is a warning.