gistfile1.cs

//Extensions.cs
public static IObservable<T> ObservableFunc<T>(this Func<T> f) {
    return Observable.Create<T>(obs => {
        try {
            obs.OnNext(f());
            obs.OnCompleted();
        } catch (Exception e) {
            obs.OnError(e);
        }
        return () => {};
    });
}

//Other.cs
var info = Observable
                .Interval(TimeSpan.FromMilliseconds(450))
                .SelectMany(_ => getInfo.ObservableFunc()) // getInfo is a Func<T> that can throw
                .TakeUntil(done);