dbclient reports integrity errors with GitHub

[Laurent Bercot]

  Hello,
  dropbear-2015.67, compiled with a recent (last week) musl libc,
statically linked.
  The problem also occurs with dropbear-2014.66.

  Since a few days ago (but I'm not sure when it started; in any
case it's less than a month ago), every git pull and push over SSH
from/to GitHub fails with the following message:

dbclient: Connection to git at github.com:22 exited: Integrity error (bad packet size $N)

$N is a nonsensical number, sometimes negative, but not always.

  Connections to GitHub via the OpenSSH client *work*.
  Connections to git repositories other than GitHub via dbclient *work*.
  Connections to GitHub via dbclient *do not work*, whether my client
key is ECDSA or RSA. I don't use DSA.

  Any idea of what's going on or what I could do to learn more ?
It's probably a GitHub problem, but I figured I had more chances of
finding knowledgeable people here :)

  Thanks,

-- 
  Laurent