Public bug reported: When running a GUI application as root (apport-bug, gparted, etc.), the command invariably fails, no matter how it's run:
$ sudo xclock No protocol specified Error: Can't open display: :0 $ pkexec xclock Error: Can't open display: Workaround: root can be granted access via xhost as follows, but this is insecure on multi-user systems. $ xhost +si:localuser:root localuser:root being added to access control list ProblemType: Bug DistroRelease: Ubuntu 17.10 Package: xwayland 2:1.19.4-1ubuntu2 ProcVersionSignature: Ubuntu 4.13.0-15.16-generic 4.13.4 Uname: Linux 4.13.0-15-generic x86_64 ApportVersion: 2.20.7-0ubuntu3 Architecture: amd64 CompizPlugins: [core,composite,opengl,compiztoolbox,decor,gnomecompat,grid,imgpng,mousepoll,move,place,regex,resize,session,snap,vpswitch,wall,unitymtgrabhandles,animation,expo,ezoom,staticswitcher,workarounds,fade,scale,unityshell] CompositorRunning: None CurrentDesktop: GNOME Date: Fri Oct 13 10:14:47 2017 DistUpgraded: 2017-10-13 08:53:41,683 DEBUG Running PostInstallScript: './xorg_fix_proprietary.py' DistroCodename: artful DistroVariant: ubuntu ExtraDebuggingInterest: Yes GraphicsCard: Intel Corporation HD Graphics 5500 [8086:1616] (rev 09) (prog-if 00 [VGA controller]) Subsystem: ASUSTeK Computer Inc. HD Graphics 5500 [1043:183d] InstallationDate: Installed on 2016-12-02 (313 days ago) InstallationMedia: Ubuntu-GNOME 16.10 "Yakkety Yak" - Release amd64 (20161012.1) MachineType: ASUSTeK COMPUTER INC. UX303LAB ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-4.13.0-15-generic root=UUID=795346fb-c6f2-478b-88c6-363f7317e849 ro rootflags=subvol=@ quiet splash acpi_osi= vt.handoff=7 SourcePackage: xorg-server UpgradeStatus: Upgraded to artful on 2017-10-12 (0 days ago) dmi.bios.date: 08/25/2015 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: UX303LAB.210 dmi.board.asset.tag: ATN12345678901234567 dmi.board.name: UX303LAB dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: 1.0 dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: ASUSTeK COMPUTER INC. dmi.chassis.version: 1.0 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrUX303LAB.210:bd08/25/2015:svnASUSTeKCOMPUTERINC.:pnUX303LAB:pvr1.0:rvnASUSTeKCOMPUTERINC.:rnUX303LAB:rvr1.0:cvnASUSTeKCOMPUTERINC.:ct10:cvr1.0: dmi.product.family: UX dmi.product.name: UX303LAB dmi.product.version: 1.0 dmi.sys.vendor: ASUSTeK COMPUTER INC. version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.83-1 version.libgl1-mesa-dri: libgl1-mesa-dri 17.2.2-0ubuntu1 version.libgl1-mesa-glx: libgl1-mesa-glx 17.2.2-0ubuntu1 version.xserver-xorg-core: xserver-xorg-core 2:1.19.4-1ubuntu2 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.10.0-1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20170309-0ubuntu1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-2 ** Affects: xorg-server (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug artful ubuntu wayland-session -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1723279 Title: xwayland doesn't let root access the display, even via sudo or pkexec To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1723279/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp