ssh -Y from macOS (11.16.2 Bigsur) to FreeBSD box (12.3)

From: Christoph Kukulies <kuku_at_kukulies.org>
Date: Thu, 10 Feb 2022 07:58:40 UTC
I recall it had workd in the past but something must have changed. 
I’m trying to do the following



 ssh -Y -v pc235
OpenSSH_8.1p1, LibreSSL 2.7.3
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 47: Applying options for *
debug1: Connecting to pc235 port 22.
debug1: Connection established.
debug1: identity file /Users/kuku/.ssh/id_rsa type 0
debug1: identity file /Users/kuku/.ssh/id_rsa-cert type -1
debug1: identity file /Users/kuku/.ssh/id_dsa type -1
debug1: identity file /Users/kuku/.ssh/id_dsa-cert type -1
debug1: identity file /Users/kuku/.ssh/id_ecdsa type -1
debug1: identity file /Users/kuku/.ssh/id_ecdsa-cert type -1
debug1: identity file /Users/kuku/.ssh/id_ed25519 type 3
debug1: identity file /Users/kuku/.ssh/id_ed25519-cert type -1
debug1: identity file /Users/kuku/.ssh/id_xmss type -1
debug1: identity file /Users/kuku/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.1
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.9 FreeBSD-20200214
debug1: match: OpenSSH_7.9 FreeBSD-20200214 pat OpenSSH* compat 0x04000000
debug1: Authenticating to pc235:22 as 'kuku'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:xxxxxxxxxx
debug1: Host 'pc235' is known and matches the ECDSA host key.
debug1: Found key in /Users/kuku/.ssh/known_hosts:7
debug1: rekey out after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: rekey in after 134217728 blocks
debug1: Will attempt key: /Users/kuku/.ssh/id_rsa RSA SHA256:xxxxxxxxx
debug1: Will attempt key: /Users/kuku/.ssh/id_dsa 
debug1: Will attempt key: /Users/kuku/.ssh/id_ecdsa 
debug1: Will attempt key: /Users/kuku/.ssh/id_ed25519 ED25519 SHA256:xxxxxxx
debug1: Will attempt key: /Users/kuku/.ssh/id_xmss 
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<ssh-ed25519,ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,keyboard-interactive
debug1: Next authentication method: publickey
debug1: Offering public key: /Users/kuku/.ssh/id_rsa RSA SHA256:xxxxxx
debug1: Server accepts key: /Users/kuku/.ssh/id_rsa RSA SHA256:xxxxxx
debug1: Authentication succeeded (publickey).
Authenticated to pc235 ([192.168.178.34]:22).
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: pledge: exec
debug1: client_input_global_request: rtype hostkeys-00@openssh.com want_reply 0
debug1: Remote: /home/kuku/.ssh/authorized_keys:1: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding
debug1: Remote: /home/kuku/.ssh/authorized_keys:1: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding
debug1: No xauth program.
Warning: No xauth data; using fake authentication data for X11 forwarding.
debug1: Requesting X11 forwarding with authentication spoofing.
debug1: Sending environment.
debug1: Sending env LANG = de_DE.UTF-8
Last login: Thu Feb 10 08:44:31 2022 from christophs-macbook-pro.fritz.box
FreeBSD 12.3-RELEASE-p1 GENERIC 

Welcome to FreeBSD!


$ echo $DISPLAY
localhost:10.0
$ xclock
connect /tmp/.X11-unix/X0: No such file or directory
Error: Can't open display: localhost:10.0

Any clues?


Christoph Kukulies