Umar bin Khattab reported,
Three matters about which I would have preferred the Messenger of Allah ﷺ to have given a clear ruling, more dearly than the world and all it contains, are kalalah, riba, and the caliphate.
Ibn Majah 2727
Daifحدثنا علي بن محمد وأبو بكر بن أبى شيبة قالا حدثنا وكيع حدثنا سفيان حدثنا عمرو بن مرة عن مرة بن شراحيل قال
قال عمر بن الخطاب
ثلاث لأن يكون رسول الله ﷺ بينهن أحب إلي من الدنيا وما فيها الكلالة والربا والخلافة
No references are available.
Its chain is daif. Busiri stated that it is munqati, and he related from Abu Hatim Razi that on one occasion he said it was a mursal narration from Umar. Bukhari, no. 5588, and Muslim, no. 3032, and others narrated from Umar 
that he said, "There are three matters I wish the Messenger of Allah ﷺ had not left us before giving us a clear ruling about them, the grandfather's inheritance, the kalalah, and some of the matters of riba," but he did not mention the caliphate.