Salut à tous,
Je rencontre un problème avec la commande xinit, qui si je me rappelle bien fonctionnait correctement avec F20 et avec certitude sous F18. Je m'explique je veux l'utiliser pour déporter l'affichage de mon Raspberry pi avec ces commandes : 
# Sur mon pc
# xinit -- :1 &
$ DISPLAY=:1 ssh -X pi@raspberrypi lxsession
La commande xinit retourne des erreurs que je n'arrive pas à décoder 
[  1824.875] 
X.Org X Server 1.16.3
Release Date: 2014-12-20
[  1824.875] X Protocol Version 11, Revision 0
[  1824.875] Build Operating System:  3.17.8-300.bz1178975.fc21.x86_64 
[  1824.876] Current Operating System: Linux Conquering-Lion2 3.19.5-200.fc21.x86_64 #1 SMP Mon Apr 20 19:51:56 UTC 2015 x86_64
[  1824.876] Kernel command line: BOOT_IMAGE=/vmlinuz-3.19.5-200.fc21.x86_64 root=/dev/mapper/fedora_conquering--lion2-root ro rd.md=0 rd.dm=0 rd.lvm.lv=fedora_conquering-lion2/swap vconsole.keymap=fr rd.luks=0 rd.lvm.lv=fedora_conquering-lion2/root rhgb quiet LANG=fr_FR.UTF-8 acpi_backlight=vendor
[  1824.876] Build Date: 31 January 2015  11:23:27PM
[  1824.876] Build ID: xorg-x11-server 1.16.3-2.fc21 
[  1824.876] Current version of pixman: 0.32.6
[  1824.876]    Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
[  1824.876] Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[  1824.876] (==) Log file: "/var/log/Xorg.1.log", Time: Sat May  9 18:17:32 2015
[  1824.877] (==) Using config directory: "/etc/X11/xorg.conf.d"
[  1824.877] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[  1824.877] (==) No Layout section.  Using the first Screen section.
[  1824.877] (==) No screen section available. Using defaults.
[  1824.877] (**) |-->Screen "Default Screen Section" (0)
[  1824.877] (**) |   |-->Monitor "<default monitor>"
[  1824.877] (==) No monitor specified for screen "Default Screen Section".
        Using a default monitor configuration.
[  1824.877] (==) Automatically adding devices
[  1824.877] (==) Automatically enabling devices
[  1824.877] (==) Automatically adding GPU devices
[  1824.877] (==) FontPath set to:
        catalogue:/etc/X11/fontpath.d,
        built-ins
[  1824.877] (==) ModulePath set to "/usr/lib64/xorg/modules"
[  1824.877] (II) The server relies on udev to provide the list of input devices.
        If no devices become available, reconfigure udev or disable AutoAddDevices.
[  1824.877] (II) Loader magic: 0x81de40
[  1824.877] (II) Module ABI versions:
[  1824.877]    X.Org ANSI C Emulation: 0.4
[  1824.877]    X.Org Video Driver: 18.0
[  1824.877]    X.Org XInput driver : 21.0
[  1824.877]    X.Org Server Extension : 8.0
[  1824.884] (II) systemd-logind: took control of session /org/freedesktop/login1/session/_31
[  1824.885] (II) xfree86: Adding drm device (/dev/dri/card0)
[  1824.885] (II) systemd-logind: got fd for /dev/dri/card0 226:0 fd 10 paused 1
[  1824.886] (EE) Error systemd-logind returned paused fd for drm node
[  1824.886] (II) systemd-logind: releasing fd for 226:0
[  1824.887] (--) PCI:*(0:0:2:0) 8086:0166:1179:0004 rev 9, Mem @ 0xe0000000/4194304, 0xd0000000/268435456, I/O @ 0x00002000/64, BIOS @ 0x????????/131072
[  1824.887] (II) LoadModule: "glx"
[  1824.887] (II) Loading /usr/lib64/xorg/modules/extensions/libglx.so
[  1824.889] (II) Module glx: vendor="X.Org Foundation"
[  1824.889]    compiled for 1.16.3, module version = 1.0.0
[  1824.889]    ABI class: X.Org Server Extension, version 8.0
[  1824.889] (==) AIGLX enabled
[  1824.889] (==) Matched intel as autoconfigured driver 0
[  1824.889] (==) Matched modesetting as autoconfigured driver 1
[  1824.889] (==) Matched fbdev as autoconfigured driver 2
[  1824.889] (==) Matched vesa as autoconfigured driver 3
[  1824.889] (==) Assigned the driver to the xf86ConfigLayout
[  1824.889] (II) LoadModule: "intel"
[  1824.889] (II) Loading /usr/lib64/xorg/modules/drivers/intel_drv.so
[  1824.889] (II) Module intel: vendor="X.Org Foundation"
[  1824.889]    compiled for 1.16.1, module version = 2.99.916
[  1824.889]    Module class: X.Org Video Driver
[  1824.889]    ABI class: X.Org Video Driver, version 18.0
[  1824.889] (II) LoadModule: "modesetting"
[  1824.889] (II) Loading /usr/lib64/xorg/modules/drivers/modesetting_drv.so
[  1824.889] (II) Module modesetting: vendor="X.Org Foundation"
[  1824.889]    compiled for 1.16.0, module version = 0.9.0
[  1824.889]    Module class: X.Org Video Driver
[  1824.889]    ABI class: X.Org Video Driver, version 18.0
[  1824.889] (II) LoadModule: "fbdev"
[  1824.889] (II) Loading /usr/lib64/xorg/modules/drivers/fbdev_drv.so
[  1824.889] (II) Module fbdev: vendor="X.Org Foundation"
[  1824.890]    compiled for 1.16.0, module version = 0.4.3
[  1824.890]    Module class: X.Org Video Driver
[  1824.890]    ABI class: X.Org Video Driver, version 18.0
[  1824.890] (II) LoadModule: "vesa"
[  1824.890] (II) Loading /usr/lib64/xorg/modules/drivers/vesa_drv.so
[  1824.890] (II) Module vesa: vendor="X.Org Foundation"
[  1824.890]    compiled for 1.16.0, module version = 2.3.2
[  1824.890]    Module class: X.Org Video Driver
[  1824.890]    ABI class: X.Org Video Driver, version 18.0
[  1824.890] (II) intel: Driver for Intel(R) Integrated Graphics Chipsets:
        i810, i810-dc100, i810e, i815, i830M, 845G, 854, 852GM/855GM, 865G,
        915G, E7221 (i915), 915GM, 945G, 945GM, 945GME, Pineview GM,
        Pineview G, 965G, G35, 965Q, 946GZ, 965GM, 965GME/GLE, G33, Q35, Q33,
        GM45, 4 Series, G45/G43, Q45/Q43, G41, B43
[  1824.890] (II) intel: Driver for Intel(R) HD Graphics: 2000-6000
[  1824.890] (II) intel: Driver for Intel(R) Iris(TM) Graphics: 5100, 6100
[  1824.890] (II) intel: Driver for Intel(R) Iris(TM) Pro Graphics: 5200, 6200, P6300
[  1824.890] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[  1824.890] (II) FBDEV: driver for framebuffer: fbdev
[  1824.890] (II) VESA: driver for VESA chipsets: vesa
[  1824.890] (--) using VT number 2

[  1824.917] (II) intel(0): Using Kernel Mode Setting driver: i915, version 1.6.0 20141121
[  1824.917] (WW) Falling back to old probe method for modesetting
[  1824.917] (WW) Falling back to old probe method for fbdev
[  1824.917] (II) Loading sub module "fbdevhw"
[  1824.917] (II) LoadModule: "fbdevhw"
[  1824.918] (II) Loading /usr/lib64/xorg/modules/libfbdevhw.so
[  1824.918] (II) Module fbdevhw: vendor="X.Org Foundation"
[  1824.918]    compiled for 1.16.3, module version = 0.0.2
[  1824.918]    ABI class: X.Org Video Driver, version 18.0
[  1824.918] (WW) Falling back to old probe method for vesa
[  1827.060] (EE) intel(0): [drm] failed to set drm interface version: Permission denied [13].
[  1827.060] (II) intel(0): [drm] Contents of '/sys/kernel/debug/dri/0/clients':
[  1827.060] (II) intel(0): [drm]              command   pid dev master a   uid      magic
[  1827.060] (II) intel(0): [drm]             Xorg.bin   893   0   y    y     0          0
[  1827.060] (II) intel(0): [drm]             Xorg.bin   893   0   n    y     0          3
[  1827.060] (II) intel(0): [drm]       systemd-logind   793   0   n    y     0          0
[  1827.060] (II) intel(0): [drm]             Xorg.bin 13809   0   n    y     0          0
[  1827.060] (EE) intel(0): Failed to claim DRM device.
[  1827.060] (II) UnloadModule: "intel"
[  1827.060] (EE) Screen(s) found, but none have a usable configuration.
[  1827.060] (EE) 
Fatal server error:
[  1827.060] (EE) no screens found(EE) 
[  1827.060] (EE) 
Please consult the Fedora Project support 
         at http://wiki.x.org
 for help. 
[  1827.060] (EE) Please also check the log file at "/var/log/Xorg.1.log" for additional information.
[  1827.060] (EE) 
[  1827.068] (EE) Server terminated with error (1). Closing log file.
Help please !
[ 1827.060] (EE) Screen(s) found, but none have a usable configuration.
Le serveur ne trouve pas de configuration fonctionnelle.
Merci de ta réponse nouvo09, en cherchant pas mal de temps j'ai trouver la raison sur le net => SYSTEMD <= (je déteste ce truc mais bon on va pas troller). Bref les modifications font que le serveur peut etre lancé par autre que root, et qu'il faut maintenant lier xinit au terminal virtual à partir duquel il est lancé. Un truc dans le genre (pour TTY2) : 
xinit -- :1 vt2
Bref très frustré parce que je ne trouve jamais une doc qui marche pour systemd ( cf les fichier units non détectés dans /etc/systemd/system, etc...) et qu'ils sont pas tres réactif sur IRC :-?
C'est surtout que systemd est encore jeune et que souvent les doc sont fait pas des utilisateurs de debian qui sont moins réactif que ceux de redhat/fedora. Le souci aussi c'est que la manière de travailler change et donc ça emmerd... pose des problèmes aux gens.

Si tu trouve la solution n'hésite pas à le dire, ça permet d'aider les personnes dans le même cas que toi 😉.

D'ailleurs cela vas m'aider car je suis entrain de voir le même genre de sujet.
Oui j'essaye toujours de joindre l'acte à la parole 😉
En parlant de réactivité de notre bien aimé OS, j'ai le sentiment qu'elle a bien diminuer par rapport à il y a quelques années que ce soit en terme de nouveau paquets disponibles ou encore le temps qu'on a mis a proposer une distrib pour le RPi par ex.
Tu peux essayer de corriger cela en te joignant aux développeurs/testeurs.