SSH cloning in sourcegraph/server (not cluster) is entirely broken

Created by: slimsag

Looking into a separate SSH cloning issue, I realized that SSH cloning in sourcegraph/server is entirely broken. All clones fail with:

The remote repository is unreachable. Logs follow.

repo not found (name=192.168.1.9/MP/mux5 url=ssh://[email protected]:7999/mp/mux5.git notfound=true) because exit status 128 (output follows)

Error relocating /usr/bin/ssh: explicit_bzero: symbol not found
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

It is easy to reproduce:

$ docker run --entrypoint='' sourcegraph/server:3.0.0-beta ssh
Error relocating /usr/bin/ssh: explicit_bzero: symbol not found

And easy to prove it doesn't affect cluster deployments (why?)

$ docker run --entrypoint='' sourcegraph/gitserver:3.0.0-beta ssh
usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]
           [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]
           [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]
           [-i identity_file] [-J [user@]host[:port]] [-L address]
           [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]
           [-Q query_option] [-R address] [-S ctl_path] [-W host:port]
           [-w local_tun[:remote_tun]] destination [command]