bug#24049: GuixSD - problem with X11 forwarding

[myglc2 <myglc2@gmail.com>]

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This is still open so I am moving it from user to bugs ...

From: myglc2 <myglc2@gmail.com>
Subject: Re: guixSD - problem with X11 forwarding
Newsgroups: gmane.comp.gnu.guix.user
To: help-guix@gnu.org
Date: Mon, 29 Feb 2016 21:12:51 -0500 (20 weeks, 2 days, 14 hours ago)

ludo@gnu.org (Ludovic Courtès) writes:

> myglc2 <myglc2@gmail.com> skribis:
>
>> On guixSD, with no packages installed in the login user profile, I get
>> 'X11 forwarding request failed on channel 0'
>
> [...]
>
>> debug1: channel 0: new [client-session]
>> debug1: Entering interactive session.
>> debug1: Requesting X11 forwarding with authentication spoofing.
>> debug1: Sending environment.
>> debug1: Sending env LANG = en_US.UTF-8
>> X11 forwarding request failed on channel 0
>
> Right, I see that as well.
>
> lshd gives some clues in /var/log/messages:
>
> Feb 23 18:14:09 localhost lshd[430]: lshd: Updating utmp for login failed (errno = 2): No such file or directory 
> Feb 23 18:14:09 localhost lshd[430]: lshd: xauth invocation failed: exit code: 127 
> Feb 23 18:14:33 localhost lshd[430]: lshd: Updating utmpx for logout failed (errno = 2): No such file or directory 
> Feb 23 18:14:33 localhost lshd[430]: lshd: write_buffer: Attempt to write data to closed buffer. 
> Feb 23 18:14:33 localhost lshd[430]: lshd: Disconnect for reason 11: disconnected by user 
>
> Indeed, server_x11.c in lsh reads:
>
> #ifndef XAUTH_PROGRAM
> # define XAUTH_PROGRAM "/usr/X11R6/bin/xauth"
> #endif
>
> I believe this is fixed by commit da35acf.

[...]

Not, at lease, in my setup. I am running GuixSD built from git checkout ...

b006ba5 [behind 15] pull:  Update the version string.
  
On the client, ssh produces ...

'X11 forwarding request failed on channel 0'

On the headless server (g1) in /var/log/messages ...

Jul 21 12:24:51 localhost lshd[381]: lshd: Failed to cd to `/tmp/.X11-unix' (errno = 2): No such file or directory 
Jul 21 12:24:51 localhost lshd[381]: lshd: Updating utmp for login failed (errno = 2): No such file or directory 

With this workaround ...

sudo mkdir /tmp/.X11-unix
sudo chmod 777 /tmp/.X11-unix

... if I log out and back in X11 forwarding "works" and in
/var/log/messages ...

Jul 21 12:33:44 localhost lshd[381]: lshd: Updating utmp for login failed (errno = 2): No such file or directory

When I logout, in /var/log/messages I see ...

Jul 21 12:36:06 localhost lshd[381]: lshd: Updating utmpx for logout failed (errno = 2): No such file or directory 
Jul 21 12:36:06 localhost lshd[381]: lshd: write_buffer: Attempt to write data to closed buffer. 
Jul 21 12:36:06 localhost lshd[381]: lshd: Disconnect for reason 11: disconnected by user

Of course, the workaround needs to be re-applied each time the server is
rebooted.

The system and user configs are attached below ;-)


[-- Attachment #2: g1.scm --]
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(use-package-modules
 aspell
 base
 scheme ;; sicp
 emacs  ;; geiser-next
 )
(packages->manifest
 (list
  aspell-dict-en ; because emacs doesn't find system install
  geiser-next    ; temporary for 'C-c C-d C-d' to work
  sicp           ; SICP in texinfo
  ))

[-- Attachment #3: system.scm --]
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;;; g1 system config
(use-modules (gnu))
(use-service-modules networking ssh)
(use-package-modules
 base
 admin
 disk
 linux                 ; mdadm
 package-management    ; guix
 screen
 ghostscript           ; gs-fonts
 fonts                 ; font-dejavu font-gnu-freefont-ttf
 curl                  ;lpaste
 ssh
 rsync
 wget
 version-control       ; git
 aspell
 emacs
 autotools             ; automake
 texinfo
 gettext
 xorg certs
 graphviz
 qemu
 )
(operating-system
  (host-name "g1")
  (timezone "America/New_York")
  (locale "en_US.utf8")
  (bootloader (grub-configuration (device "/dev/sda")))
  (file-systems (cons (file-system
			(device "g1sd")
			(title 'label)
			(mount-point "/")
			(type "ext4"))
		      %base-file-systems))
  (users (cons* (user-account
		 (name "glc")
		 (group "users")
		 (supplementary-groups '("wheel"))
		 (home-directory "/home/glc"))
		(user-account
		 (name "g1")
		 (group "users")
		 (supplementary-groups '("wheel" "kvm"))
		 (home-directory "/home/g1"))
		(user-account
		 (name "g1x")
		 (group "users")
		 (supplementary-groups '("wheel" "kvm"))
		 (home-directory "/home/g1x"))
		%base-user-accounts))
  (packages
   (cons*
    glibc-utf8-locales
    parted
    mdadm
    qemu
    guix
    screen
    openssh nss-certs xauth
    rsync wget
    curl ;lpaste
    git git-manpages
    gs-fonts font-dejavu font-gnu-freefont-ttf
    aspell-dict-en 
    emacs
    flycheck paredit magit
    emacs-zenburn-theme emacs-markdown-mode emacs-web-mode 
    gnu-make
    texinfo
    automake
    graphviz
    %base-packages))
  (services (cons* (dhcp-client-service)
		   (lsh-service #:port-number 22)
		   %base-services)))