Hello,
I believe I'm facing the same issue after my yesterday's update, with method http.
[20:51] <nicodache@tcherepnin> ~ $ sudo apt-get update
Réception de:1 http://ftp.belnet.be/debian sid InRelease [235 kB]
Lecture des listes de paquets... Fait
E: Method http has died unexpectedly!
E: Le sous-processus http a reçu le signal 31
[20:51] <nicodache@tcherepnin> ~ $ apt --version
apt 1.6~alpha1 (amd64)
Do you confirm the cause appears similar ?
FWIW, I've had the same error with method https (which I use for non-free Opera web browser).
Thanks
-- N