Capistrano stopped deploying due to ssh authorization error. Where to dig?

Question

SSH

Rails 3, ruby ​​1.9.2, ubuntu, nginx, unicorn, capistrano
Deployment takes place from a repository on bitbucket.org using deployment keys. The last time I deployed was in December 2013, I tried it today - it doesn't work. When executed, cap deployit gives

Error reading response length from authentication socket.

What I tried to do:
- Created a new pair of keys on the server.
- added a new public key from the server to the repository.
The result is the same.
A piece of the output of the command cap deploywith an error:

* ←[33mexecuting "if [ -d /sites/user1/project/deploy/shared/cached-copy ];
 then cd /sites/user1/project/deploy/shared/cached-copy && git fetch -q origi
n && git fetch --tags -q origin && git reset -q --hard 469ea5a1f2bf60d6122b0f129
6d59198a6e8d5fb && git clean -q -d -x -f; else git clone -q -b master [email protected]
ket.org:poloten4ik/bz.git /sites/user1/project/deploy/shared/cached-copy && c
d /sites/user1/project/deploy/shared/cached-copy && git checkout -q -b deploy
 469ea5a1f2bf60d6122b0f1296d59198a6e8d5fb; fi"←[0m
    servers: ["85.17.194.217"]
    [85.17.194.217] executing command
 ** [85.17.194.217 :: out] Error reading response length from authentication soc
ket.
 ** [85.17.194.217 :: out] Error reading response length from authentication soc
ket.
    ←[2;37mcommand finished in 4150ms←[0m
    copying the cached version to /sites/user1/project/deploy/releases/201402
23201009

Answer 1

set :ssh_options, { :forward_agent => false }

Answer 2

Have you tried manually logging in via ssh on behalf of the user who is doing the deployment to a remote server?

Answer 3

Look here

Answer 4

@p00h so in @badcluster's case did bitbucket update openssh or is he on his own machine?
what is the client here what is the server?