Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751738AbeACDeX (ORCPT + 1 other); Tue, 2 Jan 2018 22:34:23 -0500 Received: from mail-ua0-f172.google.com ([209.85.217.172]:34132 "EHLO mail-ua0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751185AbeACDeV (ORCPT ); Tue, 2 Jan 2018 22:34:21 -0500 X-Google-Smtp-Source: ACJfBotdbAGKix6NTiWhUlU0l/ABYs5tgdU2DqOp8E8zDuZVlvohO7tZSujnA7uPsXc719k3bf2lmHGkLulC5i12Sq0= MIME-Version: 1.0 In-Reply-To: References: From: Bryan Turner Date: Tue, 2 Jan 2018 19:34:04 -0800 Message-ID: Subject: Re: [ANNOUNCE] Git v2.16.0-rc0 To: Junio C Hamano , Jonathan Nieder , Brandon Williams , Ben Humphreys Cc: Git Users , Linux Kernel , git-packagers@googlegroups.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Thu, Dec 28, 2017 at 8:30 PM, Junio C Hamano wrote: > An early preview release Git v2.16.0-rc0 is now available for > testing at the usual places. It is comprised of 435 non-merge > commits since v2.15.0, contributed by 76 people, 22 of which are > new faces. > Brandon Williams (24): > ssh: introduce a 'simple' ssh variant > Jonathan Nieder (10): > ssh test: make copy_ssh_wrapper_as clean up after itself > connect: move no_fork fallback to git_tcp_connect > connect: split git:// setup into a separate function > connect: split ssh command line options into separate function > connect: split ssh option computation to its own function > ssh: 'auto' variant to select between 'ssh' and 'simple' > ssh: 'simple' variant does not support -4/-6 > ssh: 'simple' variant does not support --port > connect: correct style of C-style comment > generate-cmdlist: avoid non-deterministic output Sorry for being late to the party on the "simple" variant for SSH, but we've been doing some testing with 2.16.0-rc0 and noticed an unexpected issue. Our test environment is still on Ubuntu 12.04 LTS (it's a long story, but one I doubt is unique to us), which means it's using OpenSSH 5.9. ssh -G was added in OpenSSH 6.8 [1], circa March 2015, which means the "auto" detection "fails" and chooses "simple" instead of "ssh". But OpenSSH 5.9 _does_ support -4, -6 and -p. As a result, commands which have been working without issue on all previous versions of Git start to fail saying: git -c gc.auto=0 -c credential.helper= fetch --force --prune --progress ssh://localhost:64281/repo.git +refs/*:refs/*' exited with code 128 saying: fatal: ssh variant 'simple' does not support setting port I know Ubuntu 12.04 LTS is end-of-life, but 14.04 LTS, which is running OpenSSH 6.6 [2], has the same issue. The following is from a fully patched 14.04.5: bturner@ubuntu:~$ cat /etc/*ease | head -4 DISTRIB_ID=Ubuntu DISTRIB_RELEASE=14.04 DISTRIB_CODENAME=trusty DISTRIB_DESCRIPTION="Ubuntu 14.04.5 LTS" bturner@ubuntu:~$ ssh -V OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8, OpenSSL 1.0.1f 6 Jan 2014 bturner@ubuntu:~$ ssh -G -p 7999 localhost unknown option -- G usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec] [-D [bind_address:]port] [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11] [-i identity_file] [-L [bind_address:]port:host:hostport] [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port] [-Q cipher | cipher-auth | mac | kex | key] [-R [bind_address:]port:host:hostport] [-S ctl_path] [-W host:port] [-w local_tun[:remote_tun]] [user@]hostname [command] Is it possible to adjust the check, somehow, so it doesn't impact older OpenSSH versions like this? As it stands, it seems likely a fair number of users who have an SSH command that does support -4, -6 and -p are going to end up getting "penalized" because it doesn't also support -G, and have to manually set their SSH variant to "ssh" (or something other than "auto") to avoid the automatic detection. I'd love to say I have a brilliant idea for how to work around this, oh and here's a patch, but I don't. One option might be trying to actually review the output, and another might be to run "ssh -V", but both of those have their own flaws (and the extra process forks aren't "free"). [1] https://www.openssh.com/txt/release-6.8 [2] https://launchpad.net/ubuntu/+source/openssh Best regards, Bryan Turner