Well, I am not sure you're gonna get paid Euribor... Even if you were, recall that it's negative, so you're likely to be paying.By being short the german futures, in theory, one is getting paid Euribor and paying out the bond yield right? So what is the carry now on rolling bunds and buxls futures?
If you're short the German futures, you're (kinda) borrowing the bond in the repo mkt at (maybe) GC. That's the "funding" leg of the trade. Carry and rolldown for bunds is arnd 4.2bps per quarter and for buxl - arnd 2.1bps per quarter.