What does the -dpi option of Xephyr do. I'm trying different values like this: Xephyr -dpi 20 -screen 640x480 :1 and the programs running in the session don't look different in any way.

0. I am running a Python program where I'm trying to launch a Xephyr window to display the Isaac Gym simulation. However, when executing the line: sim = self.gym.create_sim(compute_device, graphics_device, physics_engine, sim_params) I consistently encounter the error: > Xlib: extension "GLX" missing on display ":1" System Configuration: > OS: Ubuntu 22.04 > Server (no physical display; can connect one if necessary) > GPU: NVIDIA RTX 4070 Ti Remote > Connection: SSH + X11 forwarding via GNOME 1. nvidia-smi Fri Mar 28 14:47:47 2025 +-----------------------------------------------------------------------------------------+ | NVIDIA-SMI 550.144.03 Driver Version: 550.144.03 CUDA Version: 12.4 | |-----------------------------------------+------------------------+----------------------+ | GPU Name Persistence-M | Bus-Id Disp.A | Volatile Uncorr. ECC | | Fan Temp Perf Pwr:Usage/Cap | Memory-Usage | GPU-Util Compute M. | | | | MIG M. | |=========================================+========================+======================| | 0 NVIDIA GeForce RTX 4070 Ti Off | 00000000:03:00.0 Off | N/A | | 0% 39C P8 4W / 285W | 22MiB / 12282MiB | 0% Default | | | | N/A | +-----------------------------------------+------------------------+----------------------+ +-----------------------------------------------------------------------------------------+ | Processes: | | GPU GI CI PID Type Process name GPU Memory | | ID ID Usage | |=========================================================================================| | 0 N/A N/A 32773 G /usr/lib/xorg/Xorg 9MiB | | 0 N/A N/A 32802 G /usr/bin/gnome-shell 4MiB | +-----------------------------------------------------------------------------------------+ 2. uname -r 6.8.0-52-generic 3. sudo lshw -C display *-display description: VGA compatible controller product: NVIDIA Corporation vendor: NVIDIA Corporation physical id: 0 bus info: pci@0000:03:00.0 logical name: /dev/fb0 version: a1 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress vga_controller bus_master cap_list rom fb configuration: depth=32 driver=nvidia latency=0 resolution=800,600 resources: irq:157 memory:f6000000-f6ffffff memory:e0000000-efffffff memory:f0000000-f1ffffff ioport:e000(size=128) memory:c0000-dffff 4. cat /var/log/Xorg.0.log [ 6130.862] (--) Log file renamed from "/var/log/Xorg.pid-37734.log" to "/var/log/Xorg.0.log" [ 6130.862] X.Org X Server 1.21.1.4 X Protocol Version 11, Revision 0 [ 6130.862] Current Operating System: Linux SEUVCL-7007 6.8.0-52-generic #53~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Jan 15 19:18:46 UTC 2 x86_64 [ 6130.862] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-6.8.0-52-generic root=UUID=84578564-1075-4040-86d4-984ad0402cdf ro quiet splash vt.handoff=7 [ 6130.862] xorg-server 2:21.1.4-2ubuntu1.7~22.04.11 (For technical support please see http://www.ubuntu.com/support) [ 6130.862] Current version of pixman: 0.40.0 [ 6130.862] Before reporting problems, check http://wiki.x.org to make sure that you have the latest version. [ 6130.862] Markers: (--) probed, (**) from config file, (==) default setting, (++) from command line, (!!) notice, (II) informational, (WW) warning, (EE) error, (NI) not implemented, (??) unknown. [ 6130.862] (==) Log file: "/var/log/Xorg.0.log", Time: Sat Mar 22 12:59:27 2025 [ 6130.862] (==) Using system config directory "/usr/share/X11/xorg.conf.d" [ 6130.862] (==) No Layout section. Using the first Screen section. [ 6130.862] (==) No screen section available. Using defaults. [ 6130.862] (**) |-->Screen "Default Screen Section" (0) [ 6130.862] (**) | |-->Monitor "" [ 6130.863] (==) No monitor specified for screen "Default Screen Section". Using a default monitor configuration. [ 6130.863] (==) Automatically adding devices [ 6130.863] (==) Automatically enabling devices [ 6130.863] (==) Automatically adding GPU devices [ 6130.863] (==) Automatically binding GPU devices [ 6130.863] (==) Max clients allowed: 256, resource mask: 0x1fffff [ 6130.863] (WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist. [ 6130.863] Entry deleted from font path. [ 6130.863] (WW) The directory "/usr/share/fonts/X11/100dpi/" does not exist. [ 6130.863] Entry deleted from font path. [ 6130.863] (WW) The directory "/usr/share/fonts/X11/75dpi/" does not exist. [ 6130.863] Entry deleted from font path. [ 6130.863] (WW) The directory "/usr/share/fonts/X11/100dpi" does not exist. [ 6130.863] Entry deleted from font path. [ 6130.863] (WW) The directory "/usr/share/fonts/X11/75dpi" does not exist. [ 6130.863] Entry deleted from font path. [ 6130.863] (==) FontPath set to: /usr/share/fonts/X11/misc, /usr/share/fonts/X11/Type1, built-ins [ 6130.863] (==) ModulePath set to "/usr/lib/xorg/modules" [ 6130.863] (II) The server relies on udev to provide the list of input devices. If no devices become available, reconfigure udev or disable AutoAddDevices. [ 6130.863] (II) Loader magic: 0x62662edfb020 [ 6130.863] (II) Module ABI versions: [ 6130.863] X.Org ANSI C Emulation: 0.4 [ 6130.863] X.Org Video Driver: 25.2 [ 6130.863] X.Org XInput driver : 24.4 [ 6130.863] X.Org Server Extension : 10.0 [ 6130.863] (++) using VT number 1 [ 6130.864] (II) systemd-logind: took control of session /org/freedesktop/login1/session/c5 [ 6130.866] (--) PCI:*(3@0:0:0) 10de:2782:1043:88dd rev 161, Mem @ 0xf6000000/16777216, 0xe0000000/268435456, 0xf0000000/33554432, I/O @ 0x0000e000/128, BIOS @ 0x????????/131072 [ 6130.866] (II) LoadModule: "glx" [ 6130.867] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so [ 6130.867] (II) Module glx: vendor="X.Org Foundation" [ 6130.867] compiled for 1.21.1.4, module version = 1.0.0 [ 6130.867] ABI class: X.Org Server Extension, version 10.0 [ 6130.984] (==) Matched nouveau as autoconfigured driver 0 [ 6130.984] (==) Matched modesetting as autoconfigured driver 1 [ 6130.984] (==) Matched fbdev as autoconfigured driver 2 [ 6130.984] (==) Matched vesa as autoconfigured driver 3 [ 6130.984] (==) Assigned the driver to the xf86ConfigLayout [ 6130.984] (II) LoadModule: "nouveau" [ 6130.984] (II) Loading /usr/lib/xorg/modules/drivers/nouveau_drv.so [ 6130.985] (II) Module nouveau: vendor="X.Org Foundation" [ 6130.985] compiled for 1.21.1.3, module version = 1.0.17 [ 6130.985] Module class: X.Org Video Driver [ 6130.985] ABI class: X.Org Video Driver, version 25.2 [ 6130.985] (II) LoadModule: "modesetting" [ 6130.985] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so [ 6130.985] (II) Module modesetting: vendor="X.Org Foundation" [ 6130.985] compiled for 1.21.1.4, module version = 1.21.1 [ 6130.985] Module class: X.Org Video Driver [ 6130.985] ABI class: X.Org Video Driver, version 25.2 [ 6130.985] (II) LoadModule: "fbdev" [ 6130.985] (II) Loading /usr/lib/xorg/modules/drivers/fbdev_drv.so [ 6130.985] (II) Module fbdev: vendor="X.Org Foundation" [ 6130.985] compiled for 1.21.1.3, module version = 0.5.0 [ 6130.985] Module class: X.Org Video Driver [ 6130.985] ABI class: X.Org Video Driver, version 25.2 [ 6130.985] (II) LoadModule: "vesa" [ 6130.985] (II) Loading /usr/lib/xorg/modules/drivers/vesa_drv.so [ 6130.985] (II) Module vesa: vendor="X.Org Foundation" [ 6130.985] compiled for 1.21.1.3, module version = 2.5.0 [ 6130.985] Module class: X.Org Video Driver [ 6130.985] ABI class: X.Org Video Driver, version 25.2 [ 6130.985] (II) NOUVEAU driver Date: Sat Jan 23 12:24:42 2021 -0500 [ 6130.985] (II) NOUVEAU driver for NVIDIA chipset families : ...... [ 6130.986] GeForce GTX 2xx/3xx (GT2xx) [ 6130.986] GeForce GTX 4xx/5xx (GFxxx) [ 6130.986] GeForce GTX 6xx/7xx (GKxxx) [ 6130.986] GeForce GTX 9xx (GMxxx) [ 6130.986] GeForce GTX 10xx (GPxxx) [ 6130.986] (II) modesetting: Driver for Modesetting Kernel Drivers: kms [ 6130.986] (II) FBDEV: driver for framebuffer: fbdev [ 6130.986] (II) VESA: driver for VESA chipsets: vesa [ 6131.127] (EE) [drm] Failed to open DRM device for pci:0000:03:00.0: -19 [ 6131.127] (EE) open /dev/dri/card0: No such file or directory [ 6131.127] (WW) Falling back to old probe method for modesetting [ 6131.127] (EE) open /dev/dri/card0: No such file or directory [ 6131.127] (II) Loading sub module "fbdevhw" [ 6131.127] (II) LoadModule: "fbdevhw" [ 6131.127] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so [ 6131.128] (II) Module fbdevhw: vendor="X.Org Foundation" [ 6131.128] compiled for 1.21.1.4, module version = 0.0.2 [ 6131.128] ABI class: X.Org Video Driver, version 25.2 [ 6131.128] (EE) Unable to find a valid framebuffer device [ 6131.128] (WW) Falling back to old probe method for fbdev [ 6131.128] (II) Loading sub module "fbdevhw" [ 6131.128] (II) LoadModule: "fbdevhw" [ 6131.129] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so [ 6131.129] (II) Module fbdevhw: vendor="X.Org Foundation" [ 6131.129] compiled for 1.21.1.4, module version = 0.0.2 [ 6131.129] ABI class: X.Org Video Driver, version 25.2 [ 6131.129] (EE) open /dev/fb0: No such file or directory [ 6131.129] (EE) Screen 0 deleted because of no matching config section. [ 6131.129] (II) UnloadModule: "modesetting" [ 6131.129] (EE) Screen 0 deleted because of no matching config section. [ 6131.129] (II) UnloadModule: "fbdev" [ 6131.129] (II) UnloadSubModule: "fbdevhw" [ 6131.130] (II) Loading sub module "vbe" [ 6131.130] (II) LoadModule: "vbe" [ 6131.130] (II) Loading /usr/lib/xorg/modules/libint10.so [ 6131.130] (II) Module int10: vendor="X.Org Foundation" [ 6131.130] compiled for 1.21.1.4, module version = 1.0.0 [ 6131.130] ABI class: X.Org Video Driver, version 25.2 [ 6131.130] (II) Loading sub module "int10" [ 6131.130] (II) LoadModule: "int10" [ 6131.131] (II) Loading /usr/lib/xorg/modules/libint10.so [ 6131.131] (II) Module int10: vendor="X.Org Foundation" [ 6131.131] compiled for 1.21.1.4, module version = 1.0.0 [ 6131.131] ABI class: X.Org Video Driver, version 25.2 [ 6131.131] (II) VESA(0): initializing int10 ...... [ 6131.204] (II) VESA(0): Creating default Display subsection in Screen section "Default Screen Section" for depth/fbbpp 24/32 [ 6131.204] (==) VESA(0): Depth 24, (--) framebuffer bpp 32 [ 6131.204] (==) VESA(0): RGB weight 888 [ 6131.204] (==) VESA(0): Default visual is TrueColor [ 6131.204] (==) VESA(0): Using gamma correction (1.0, 1.0, 1.0) [ 6131.204] (II) Loading sub module "ddc" [ 6131.204] (II) LoadModule: "ddc" [ 6131.204] (II) Module "ddc" already built-in [ 6131.406] (II) VESA(0): VESA VBE DDC supported ...... [ 6132.022] (II) VESA(0): Total Memory: 256 64KB banks (16384kB) [ 6132.022] (II) VESA(0): : Using default hsync range of 31.50-48.00 kHz [ 6132.022] (II) VESA(0): : Using default vrefresh range of 50.00-70.00 Hz [ 6132.022] (II) VESA(0): : Using default maximum pixel clock of 65.00 MHz [ 6132.022] (WW) VESA(0): Unable to estimate virtual size [ 6132.022] (II) VESA(0): Not using built-in mode "800x600" (no mode of this name) [ 6132.022] (II) VESA(0): Not using built-in mode "640x480" (no mode of this name) [ 6132.022] (WW) VESA(0): No valid modes left. Trying less strict filter... [ 6132.022] (II) VESA(0): : Using hsync range of 31.50-48.00 kHz [ 6132.022] (II) VESA(0): : Using vrefresh range of 50.00-70.00 Hz [ 6132.022] (II) VESA(0): : Using maximum pixel clock of 65.00 MHz [ 6132.022] (WW) VESA(0): Unable to estimate virtual size [ 6132.022] (II) VESA(0): Virtual size is 800x600 (pitch 800) [ 6132.022] (**) VESA(0): *Built-in mode "800x600" [ 6132.022] (**) VESA(0): *Built-in mode "640x480" [ 6132.022] (==) VESA(0): DPI set to (96, 96) [ 6132.022] (**) VESA(0): Using "Shadow Framebuffer" [ 6132.022] (II) Loading sub module "shadow" [ 6132.022] (II) LoadModule: "shadow" [ 6132.022] (II) Loading /usr/lib/xorg/modules/libshadow.so [ 6132.022] (II) Module shadow: vendor="X.Org Foundation" [ 6132.022] compiled for 1.21.1.4, module version = 1.1.0 [ 6132.022] ABI class: X.Org ANSI C Emulation, version 0.4 [ 6132.022] (II) Loading sub module "fb" [ 6132.022] (II) LoadModule: "fb" [ 6132.022] (II) Module "fb" already built-in [ 6132.022] (II) Loading sub module "int10" [ 6132.022] (II) LoadModule: "int10" [ 6132.022] (II) Loading /usr/lib/xorg/modules/libint10.so [ 6132.022] (II) Module int10: vendor="X.Org Foundation" [ 6132.022] compiled for 1.21.1.4, module version = 1.0.0 [ 6132.022] ABI class: X.Org Video Driver, version 25.2 [ 6132.022] (II) VESA(0): initializing int10 [ 6132.022] (II) VESA(0): Primary V_BIOS segment is: 0xc000 [ 6132.046] (II) VESA(0): VESA BIOS detected [ 6132.046] (II) VESA(0): VESA VBE Version 3.0 [ 6132.046] (II) VESA(0): VESA VBE Total Mem: 16384 kB [ 6132.046] (II) VESA(0): VESA VBE OEM: NVIDIA [ 6132.046] (II) VESA(0): VESA VBE OEM Software Rev: 149.4 [ 6132.046] (II) VESA(0): VESA VBE OEM Vendor: NVIDIA Corporation [ 6132.046] (II) VESA(0): VESA VBE OEM Product: GPU Board [ 6132.046] (II) VESA(0): VESA VBE OEM Product Rev: Chip Rev [ 6132.046] (II) VESA(0): virtual address = 0x754d57702000, VGAbase = 0x754d5882e000 physical address = 0xe0000000, size = 16777216 [ 6132.049] (II) VESA(0): Setting up VESA Mode 0x115 (800x600) [ 6132.076] (==) VESA(0): Default visual is TrueColor [ 6132.076] (==) VESA(0): Backing store enabled [ 6132.076] (==) VESA(0): DPMS enabled [ 6132.076] (II) Initializing extension Generic Event Extension [ 6132.076] (II) Initializing extension SHAPE ... [ 6132.077] (II) Initializing extension XVideo [ 6132.077] (II) Initializing extension XVideo-MotionCompensation [ 6132.077] (II) Initializing extension SELinux [ 6132.077] (II) SELinux: Disabled on system [ 6132.077] (II) Initializing extension GLX [ 6132.077] (II) AIGLX: Screen 0 is not DRI2 capable [ 6132.097] (II) IGLX: Loaded and initialized swrast [ 6132.097] (II) GLX: Initialized DRISWRAST GL provider for screen 0 [ 6132.097] (II) Initializing extension XFree86-VidModeExtension [ 6132.097] (II) Initializing extension XFree86-DGA [ 6132.097] (II) Initializing extension XFree86-DRI [ 6132.097] (II) Initializing extension DRI2 [ 6132.121] (II) config/udev: Adding input device Power Button (/dev/input/event2) [ 6132.122] (**) Power Button: Applying InputClass "libinput keyboard catchall" [ 6132.122] (II) LoadModule: "libinput" [ 6132.122] (II) Loading /usr/lib/xorg/modules/input/libinput_drv.so [ 6132.123] (II) Module libinput: vendor="X.Org Foundation" [ 6132.123] compiled for 1.20.14, module version = 1.2.1 [ 6132.123] Module class: X.Org XInput Driver [ 6132.123] ABI class: X.Org XInput driver, version 24.1 [ 6132.123] (II) Using input driver 'libinput' for 'Power Button' [ 6132.123] (II) systemd-logind: got fd for /dev/input/event2 13:66 fd 23 paused 0 [ 6132.123] (**) Power Button: always reports core events [ 6132.123] (**) Option "Device" "/dev/input/event2" [ 6132.125] (II) event2 - Power Button: is tagged by udev as: Keyboard [ 6132.125] (II) event2 - Power Button: device is a keyboard [ 6132.125] (II) event2 - Power Button: device removed [ 6132.125] (**) Option "config_info" "udev:/sys/devices/LNXSYSTM:00/LNXPWRBN:00/input/input2/event2" [ 6132.125] (II) XINPUT: Adding extended input device "Power Button" (type: KEYBOARD, id 6) [ 6132.125] (**) Option "xkb_model" "pc105" [ 6132.125] (**) Option "xkb_layout" "cn" [ 6132.145] (II) event2 - Power Button: is tagged by udev as: Keyboard [ 6132.145] (II) event2 - Power Button: device is a keyboard [ 6132.146] (II) config/udev: Adding input device Power Button (/dev/input/event1) [ 6132.146] (**) Power Button: Applying InputClass "libinput keyboard catchall" [ 6132.146] (II) Using input driver 'libinput' for 'Power Button' [ 6132.146] (II) systemd-logind: got fd for /dev/input/event1 13:65 fd 26 paused 0 [ 6132.146] (**) Power Button: always reports core events [ 6132.147] (**) Option "Device" "/dev/input/event1" [ 6132.147] (II) event1 - Power Button: is tagged by udev as: Keyboard [ 6132.147] (II) event1 - Power Button: device is a keyboard [ 6132.147] (II) event1 - Power Button: device removed [ 6132.147] (**) Option "config_info" "udev:/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0C:00/input/input1/event1" [ 6132.147] (II) XINPUT: Adding extended input device "Power Button" (type: KEYBOARD, id 7) [ 6132.147] (**) Option "xkb_model" "pc105" [ 6132.147] (**) Option "xkb_layout" "cn" [ 6132.148] (II) event1 - Power Button: is tagged by udev as: Keyboard [ 6132.148] (II) event1 - Power Button: device is a keyboard [ 6132.149] (II) config/udev: Adding input device Sleep Button (/dev/input/event0) [ 6132.149] (**) Sleep Button: Applying InputClass "libinput keyboard catchall" [ 6132.149] (II) Using input driver 'libinput' for 'Sleep Button' [ 6132.149] (II) systemd-logind: got fd for /dev/input/event0 13:64 fd 27 paused 0 [ 6132.149] (**) Sleep Button: always reports core events [ 6132.149] (**) Option "Device" "/dev/input/event0" [ 6132.150] (II) event0 - Sleep Button: is tagged by udev as: Keyboard [ 6132.150] (II) event0 - Sleep Button: device is a keyboard [ 6132.150] (II) event0 - Sleep Button: device removed [ 6132.150] (**) Option "config_info" "udev:/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0E:00/input/input0/event0" [ 6132.150] (II) XINPUT: Adding extended input device "Sleep Button" (type: KEYBOARD, id 8) [ 6132.150] (**) Option "xkb_model" "pc105" [ 6132.150] (**) Option "xkb_layout" "cn" [ 6132.151] (II) event0 - Sleep Button: is tagged by udev as: Keyboard [ 6132.151] (II) event0 - Sleep Button: device is a keyboard [ 6132.151] (II) config/udev: Adding input device HDA NVidia HDMI/DP,pcm=3 (/dev/input/event5) [ 6132.151] (II) No input driver specified, ignoring this device. [ 6132.151] (II) This device may have been added with another device file. [ 6132.151] (II) config/udev: Adding input device HDA NVidia HDMI/DP,pcm=7 (/dev/input/event6) [ 6132.151] (II) No input driver specified, ignoring this device. [ 6132.151] (II) This device may have been added with another device file. [ 6132.152] (II) config/udev: Adding input device HDA NVidia HDMI/DP,pcm=8 (/dev/input/event7) [ 6132.152] (II) No input driver specified, ignoring this device. [ 6132.152] (II) This device may have been added with another device file. [ 6132.152] (II) config/udev: Adding input device HDA NVidia HDMI/DP,pcm=9 (/dev/input/event8) [ 6132.152] (II) No input driver specified, ignoring this device. [ 6132.152] (II) This device may have been added with another device file. [ 6132.153] (II) config/udev: Adding input device HDA Intel PCH Rear Mic (/dev/input/event10) [ 6132.153] (II) No input driver specified, ignoring this device. [ 6132.153] (II) This device may have been added with another device file. [ 6132.153] (II) config/udev: Adding input device HDA Intel PCH Line (/dev/input/event11) [ 6132.153] (II) No input driver specified, ignoring this device. [ 6132.153] (II) This device may have been added with another device file. [ 6132.153] (II) config/udev: Adding input device HDA Intel PCH Line Out Front (/dev/input/event12) [ 6132.153] (II) No input driver specified, ignoring this device. [ 6132.153] (II) This device may have been added with another device file. [ 6132.154] (II) config/udev: Adding input device HDA Intel PCH Line Out Surround (/dev/input/event13) [ 6132.154] (II) No input driver specified, ignoring this device. [ 6132.154] (II) This device may have been added with another device file. [ 6132.154] (II) config/udev: Adding input device HDA Intel PCH Line Out CLFE (/dev/input/event14) [ 6132.154] (II) No input driver specified, ignoring this device. [ 6132.154] (II) This device may have been added with another device file. [ 6132.154] (II) config/udev: Adding input device HDA Intel PCH Line Out Side (/dev/input/event15) [ 6132.154] (II) No input driver specified, ignoring this device. [ 6132.154] (II) This device may have been added with another device file. [ 6132.155] (II) config/udev: Adding input device HDA Intel PCH Front Headphone (/dev/input/event16) [ 6132.155] (II) No input driver specified, ignoring this device. [ 6132.155] (II) This device may have been added with another device file. [ 6132.155] (II) config/udev: Adding input device HDA Intel PCH Front Mic (/dev/input/event9) [ 6132.155] (II) No input driver specified, ignoring this device. [ 6132.155] (II) This device may have been added with another device file. [ 6410.027] (II) event2 - Power Button: device removed [ 6410.028] (II) event0 - Sleep Button: device removed [ 6410.028] (II) event1 - Power Button: device removed [ 6410.028] (II) systemd-logind: got pause for 13:66 [ 6410.028] (II) systemd-logind: got pause for 13:64 [ 6410.028] (II) systemd-logind: got pause for 13:65 [ 70275.131] (II) config/udev: removing device Power Button [ 70275.132] (II) UnloadModule: "libinput" [ 70275.132] (II) systemd-logind: releasing fd for 13:66 [ 70275.133] (II) config/udev: Adding input device Power Button (/dev/input/event2) [ 70275.133] (**) Power Button: Applying InputClass "libinput keyboard catchall" [ 70275.133] (II) Using input driver 'libinput' for 'Power Button' [ 70275.135] (II) systemd-logind: got fd for /dev/input/event2 13:66 fd 33 paused 1 [ 70275.135] (II) systemd-logind: releasing fd for 13:66 [ 70275.143] (II) config/udev: Adding input device HDA Intel PCH Front Mic (/dev/input/event9) [ 70275.143] (II) No input driver specified, ignoring this device. [ 70275.143] (II) This device may have been added with another device file. [ 70275.143] (II) config/udev: Adding input device HDA Intel PCH Line Out Front (/dev/input/event12) [ 70275.143] (II) No input driver specified, ignoring this device. [ 70275.143] (II) This device may have been added with another device file. [ 70275.144] (II) config/udev: Adding input device HDA NVidia HDMI/DP,pcm=7 (/dev/input/event6) [ 70275.145] (II) No input driver specified, ignoring this device. [ 70275.145] (II) This device may have been added with another device file. [ 70275.146] (II) config/udev: Adding input device HDA Intel PCH Line (/dev/input/event11) [ 70275.146] (II) No input driver specified, ignoring this device. [ 70275.146] (II) This device may have been added with another device file. [ 70275.146] (II) config/udev: Adding input device HDA NVidia HDMI/DP,pcm=8 (/dev/input/event7) [ 70275.146] (II) No input driver specified, ignoring this device. [ 70275.146] (II) This device may have been added with another device file. [ 70275.147] (II) config/udev: Adding input device HDA Intel PCH Rear Mic (/dev/input/event10) [ 70275.147] (II) No input driver specified, ignoring this device. [ 70275.147] (II) This device may have been added with another device file. [ 70275.147] (II) config/udev: Adding input device HDA Intel PCH Line Out Side (/dev/input/event15) [ 70275.147] (II) No input driver specified, ignoring this device. [ 70275.147] (II) This device may have been added with another device file. [ 70275.147] (II) config/udev: Adding input device HDA Intel PCH Line Out Surround (/dev/input/event13) [ 70275.148] (II) No input driver specified, ignoring this device. [ 70275.148] (II) This device may have been added with another device file. [ 70275.148] (II) config/udev: removing device Sleep Button [ 70275.148] (II) UnloadModule: "libinput" [ 70275.148] (II) systemd-logind: releasing fd for 13:64 [ 70275.159] (II) config/udev: Adding input device Sleep Button (/dev/input/event0) [ 70275.160] (**) Sleep Button: Applying InputClass "libinput keyboard catchall" [ 70275.160] (II) Using input driver 'libinput' for 'Sleep Button' [ 70275.164] (II) systemd-logind: got fd for /dev/input/event0 13:64 fd 33 paused 1 [ 70275.164] (II) systemd-logind: releasing fd for 13:64 [ 70275.171] (II) config/udev: removing device Power Button [ 70275.171] (II) UnloadModule: "libinput" [ 70275.171] (II) systemd-logind: releasing fd for 13:65 [ 70275.173] (II) config/udev: Adding input device Power Button (/dev/input/event1) [ 70275.173] (**) Power Button: Applying InputClass "libinput keyboard catchall" [ 70275.173] (II) Using input driver 'libinput' for 'Power Button' [ 70275.173] (II) systemd-logind: got fd for /dev/input/event1 13:65 fd 24 paused 1 [ 70275.173] (II) systemd-logind: releasing fd for 13:65 [ 70275.180] (II) config/udev: Adding input device HDA NVidia HDMI/DP,pcm=9 (/dev/input/event8) [ 70275.180] (II) No input driver specified, ignoring this device. [ 70275.180] (II) This device may have been added with another device file. [ 70275.180] (II) config/udev: Adding input device HDA Intel PCH Line Out CLFE (/dev/input/event14) [ 70275.180] (II) No input driver specified, ignoring this device. [ 70275.180] (II) This device may have been added with another device file. [ 70275.181] (II) config/udev: Adding input device HDA Intel PCH Front Headphone (/dev/input/event16) [ 70275.181] (II) No input driver specified, ignoring this device. [ 70275.181] (II) This device may have been added with another device file. [ 70275.181] (II) config/udev: Adding input device HDA NVidia HDMI/DP,pcm=3 (/dev/input/event5) [ 70275.181] (II) No input driver specified, ignoring this device. [ 70275.181] (II) This device may have been added with another device file.

I am making heavy use of Xephyr for x11 isolation. However,acceleration does not work at all. 3d programs simply do not run, video decoding does not work, vdpau does not work, things like chromium and other things bloatd with gpu using web crap are unusably slow. I am using it like this. Xephyr -br -ac -noreset -screen 800x600 :1 DISPLAY=:1 icewm What is the issue? It's the same for when I set it up with doas or sudo.

I can use v4l2loopback to create a dummy video device, Xephyr to create a nested X server in its own window, and a gst pipeline to link the two so that the contents of the Xephyr window appear as my webcam. This gives a nice sandbox where only the applications I want to share are made visible, and it means that I can switch back to the video conference without the other participants losing the view of the nested desktop. However, this appears as my webcam, not as a screen share, and so I lose some desirable aspects of true screen sharing. For instance, it means that each other user has to "pin" my feed in order that it doesn't lose focus when someone else speaks. So I'm searching for a way to fool my browser into taking its screen share input from an X server other than the one in which it's running, or from a video device. In case it matters, this is Firefox running in a Cinnamon environment.

I have a GUI application that I want to test in parallel by running my tests in different X-servers. To do that I start the application using Xephyr or Xvnc, then I start the script to do the testing, and it works. The problem I am having is that the GUI application's CPU consumption is very high, when I run it inside Xephyr/Xvnc, such that I can't run more than one test in parallel, because of CPU limitations. When I run the gui application and check CPU usage with htop, it shows CPU% around 10 to 50%. When I run the same application with Xephyr or Xvnc, it shows CPU% around 200 to 250% (out of 4 CPUS). Xephyr/Xvnc itself does not seem to add much overhead, but the GUI application, when run inside a Xephyr/Xvnc server seems to consume 5x more CPU than normal. Is there a reason/solution for that?

I plan to run potentially dangerous applications *(browser, etc.)* on a separate X-server, but since each server has its own clipboard, it is impossible to copy the link / text from one window to another. Most articles suggest doing this using scripts using xclip and other similar utilities. But how to **CORRECTLY** create a common clipboard so as not to accidentally create a new vulnerability?

Running firefox in a SELinux sandbox using this script:

Random variables for directories, Allowing multiple instances
SEhome=$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 8 | head -n 1)
SEtemp=$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 8 | head -n 1)
mkdir /tmp/sehome.$SEhome
mkdir /tmp/setemp.$SEtemp

# run sandbox instance
sandbox -X -H /tmp/sehome.$SEhome -T /tmp/setemp.$SEtemp -t sandbox_web_t -t sandbox_net_t -w 3440x1440 firefox  --no-remote

# destroy temporary directories
rm -rf /tmp/sehome.$SEhome
rm -rf /tmp/setemp.$SEtemp

As of Fedora 38, audio no longer works. audit2allow -s is quiet and I cant really find much in the logs:
/var/log/messages

May 25 18:31:14 localhost dbus-broker: A security policy denied :1.1206 to send method call /org/freedesktop/RealtimeKit1:org.freedesktop.DBus.Properties.Get to org.freedesktop.RealtimeKit1.
May 25 18:31:14 localhost rsyslogd: imjournal: 27485 messages lost due to rate-limiting (20000 allowed within 600 seconds)

/var/log/audit/audit.log

type=CRED_ACQ msg=audit(1685032214.075:23247): pid=25443 uid=1000 auid=1000 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 msg='op=PAM:setcred grantors=pam_unix acct="root" exe="/usr/bin/su" hostname=? addr=? terminal=/dev/pts/2 res=success'UID="delta" AUID="delta"
type=USER_START msg=audit(1685032214.107:23248): pid=25443 uid=1000 auid=1000 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 msg='op=PAM:session_open grantors=pam_keyinit,pam_limits,pam_systemd,pam_unix,pam_umask,pam_xauth acct="root" exe="/usr/bin/su" hostname=? addr=? terminal=/dev/pts/2 res=success'UID="delta" AUID="delta"
type=SERVICE_START msg=audit(1685032231.705:23249): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=pcscd comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'UID="root" AUID="unset"
type=SERVICE_STOP msg=audit(1685032239.160:23250): pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg='unit=fprintd comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'UID="root" AUID="unset"
type=BPF msg=audit(1685032239.168:23251): prog-id=7441 op=UNLOAD

Any ideas on where to start? i consider myself semi-skilled at linux, but i am not a SElinux buff.

My plan is to: - Turn off listening to all sockets, and initiate X through a command such as: `Xorg -nolisten tcp -nolisten inet -nolisten inet6 -nolisten unix -nolisten local :0 -seat seat0 vt7 -novtswitch` (although I don't know how to prevent X running entirely without this configuration) - Run Xorg rootless - which is far more difficult than it seems considering I don't want to use GNOME or GDM. At the moment I'm using LightDM and XFCE. I did manage to get rootless Xorg working on SDDM, but it's quite buggy. Again the insanity of this baffles me. - FireJail the main X server and only allow communication through for specific inputs (keyboard, mouse, screen, Xephyr). So for this I'd prevent anything speaking to the X server directly other than these applications/devices, thereby forcing GUI applications to use the proxy of Xephyr. It should also keep everything sandboxed to hopefully prevent possible zero-day attacks. - Use seccomp namespacing through FireJail on both applications and the X server to try and further isolate everything However the reality of implementing these measures is much more difficult than I realised, as I've seen with FireJail and Xephyr not preventing keylogging still. Is there anything I should add to this above list? It would be good if we could compile a list in this thread of all the possible fixes to help other people out who are also probably struggling in the same way. What kind of protections do you guys have in place to prevent keylogging (and other issues) on X11 and Xorg? This is a huge issue which affects just about every GUI computer which runs Linux so I absolutely can't and don't believe there's nothing which can be done to prevent this as it's such a notorious issue. Really interested to hear what you all think.

I need to pilot an X application with my PC, to take scientific measuring. I have an xdotool script which does the job pretty well, but while it's running, I cannot use my PC, which is frustrating and cumbersome. So I thought I can run the application in a separate X server, while working in the principal. I managed to start the application and make it work in **Xephyr**, but it's fragile: Xephyr acquires my mouse when its window is visible, and it's not necessary to be focused. The grabbing function (Ctrl+Shift) kinda works, but only in one sense: I can grab the mouse, but I cannot make it **ignore** it. So my question is: is there a way to make Xephyr selectively ignore (it should be toggled on and off) my mouse and keyboard, much like it happens with a VM on VirtualBox? Thanks!

So, I started a Xephyr window: Xephyr -br -ac -noreset -screen 1280x720 :1 and then started xfce4 inside of that Xephyr X server: Export DISPLAY=:1 startxfce4 This all works fine, but now I want to get my cursor and mouse inside of that Xephyr X server... According to the arch wiki , you are apparently supposed to be able to capture user input by pressing Ctrl+Shift when the window is in focus. But, on my machine, this doesn't actually seem to do anything. So I was wondering if I am doing something wrong here? Also, I can't find anything about this keyboard combo in the manpage, does Xephyr have any documentation that covers stuff like hotkeys?

This Exact Same Question i first time i do was ib -> https://www.linuxquestions.org/questions/showthread.php?p=6366697#post6366697 i need improve my script : For close the Xephyr window automatically after click xfce4-session and for use the safest way to umount partiions after finish inside of chroot env. **---- You can ignore this part ---- :** i have write a own script (on spanish, because i am from venezuela) for mount chroot and start in gracphical env inside a Xephyr Window from Virtual HardDrive, the idea of this script is make the folow things : 01 - Run like root 02 - Mount the Hard Drive (in this case is image qcow2 format) 03 - Mount the partition 04 - Start chroot 05 - Start Xephyr 06 - Run some commands inside chroot 07 - Xephyr window start xfce4-session 08 - Wait until Xephyr finish 09 - When Xephyr finish, start the umount of partitions 10 - Finish the script with "exit 0" **---- The follow part is the important ---- :** Ok here the code i had right now : #!/usr/bin/env bash echo ' Autor ----------------> Inukaze ( Venezuela ) Sitio ----------------> https://goo.gl/ij6WqW Correo-E -------------> bloginukaze@gmail.com Licencia -------------> GPL 2 ' #Establecer mediante la variable "$OBJETIVO" #La particion con una distribucion a la cual se accedera mediante chroot export OBJETIVO="/media/ddvirt" mkdir -p "$OBJETIVO" #Prevenir que se autoejecuten las funciones que se definiran despues unset montar unset desmontar unset MensajeBase unset xephyr #Establecer y definir funciones : function MensajeBase() { echo -e "\nLa forma correcta de utilizar este guion es :\n$0 «montar» , «xephyr» ó «desmontar», Por ejemplo : \n" echo -e "$0 montar" echo -e "$0 xephyr (Modo Ventana)" echo -e "$0 desmontar\n" } function montar(){ #Desmontar en caso de que estuviera montado previamente : umount /dev/nbd0p1 2>/dev/null ; \ qemu-nbd --disconnect /dev/nbd0 1>/dev/null ; \ #Preparar para montar el disco duro virtual modprobe nbd max_part=8 qemu-nbd --connect=/dev/nbd0 /home/inukaze/.aqemu/Slack64-15.0.qcow2 2>/dev/null mount /dev/nbd0p1 "$OBJETIVO" 2>/dev/null #Preparar acceso para programas de entorno grafico : export DISPLAY=:0.0 2>/dev/null xhost + local 2>/dev/null #Montar todo de una vez para una distro de 64 Bits (En este caso Slackware64 15.0) : mount --rbind /proc "$OBJETIVO/proc" ; \ mount --make-rslave "$OBJETIVO/proc" ; \ mount --rbind /sys "$OBJETIVO/sys" ; \ mount --make-rslave "$OBJETIVO/sys" ; \ mount --rbind /dev "$OBJETIVO/dev" ; \ mount --make-rslave "$OBJETIVO/dev" ; \ mount --rbind /run "$OBJETIVO/run" ; \ mount --make-rslave "$OBJETIVO/run" ; \ mount --rbind /tmp "$OBJETIVO/tmp" ; \ mount --make-rslave "$OBJETIVO/tmp" ; \ mount --bind /etc/fstab "$OBJETIVO/etc/fstab" ; \ mount --bind /etc/hostname "$OBJETIVO/etc/hostname" ; \ mount --bind /etc/hosts "$OBJETIVO/etc/hosts" ; \ mount --bind /etc/resolv.conf "$OBJETIVO/etc/resolv.conf" ; \ cat /dev/null EOF chroot "$OBJETIVO" /bin/bash -l ; \ umount "$OBJETIVO" ; \ mount -a 2>/dev/null } function xephyr(){ umount "$OBJETIVO/etc/resolv.conf" 2>/dev/null umount "$OBJETIVO/etc/hosts" 2>/dev/null umount "$OBJETIVO/etc/hostname" 2>/dev/null umount "$OBJETIVO/etc/fstab" 2>/dev/null umount "$OBJETIVO/lib/modules" 2>/dev/null umount "$OBJETIVO/var/lib/dbus" 2>/dev/null umount "$OBJETIVO/var/run/dbus" 2>/dev/null umount "$OBJETIVO/tmp" 2>/dev/null umount "$OBJETIVO/run" 2>/dev/null umount "$OBJETIVO/dev/pts" 2>/dev/null umount -l "$OBJETIVO/dev" 2>/dev/null umount -l "$OBJETIVO/sys" 2>/dev/null umount "$OBJETIVO/proc" 2>/dev/null umount -l /dev/ndb0p1 2>/dev/null sleep 7 qemu-nbd --disconnect /dev/nbd0 1>/dev/null modprobe nbd max_part=8 qemu-nbd --connect=/dev/nbd0 /home/inukaze/.aqemu/Slack64-15.0.qcow2 sleep 3 mount /dev/nbd0p1 "$OBJETIVO" #Copiar archivo de autorizacion X.Org : rm -f "$OBJETIVO/home/inukaze/.Xauthority" rm -f "$OBJETIVO/root/.Xauthority" cp -f "/home/inukaze/.Xauthority" "$OBJETIVO/root/.Xauthority" cp -f "/home/inukaze/.Xauthority" "$OBJETIVO/home/inukaze/.Xauthority" chown inukaze:users "$OBJETIVO/home/inukaze/.Xauthority" echo "" if [ ! -f "$OBJETIVO/etc/X11/Xwrapper.config" ] ; then # Prevenir el error « /usr/libexec/Xorg.wrap: Only console users are allowed to run the X server » echo '# Xwrapper.config (Debian X Window System server wrapper configuration file) # # This file was generated by the post-installation script of the x11-common # package using values from the debconf database. # # See the Xwrapper.config(5) manual page for more information. # # This file is automatically updated on upgrades of the x11-common package # *only* if it has not been modified since the last upgrade of that package. # # If you have edited this file but would like it to be automatically updated # again, run the following command as root: # dpkg-reconfigure x11-common #allowed_users=console allowed_users=anybody' | tee "$OBJETIVO/etc/X11/Xwrapper.config" fi echo "" #Preparar acceso para programas de entorno grafico : $(export DISPLAY=:0.0) $(xhost + local 2>/dev/null) #Montar todo de una vez para una distro de 64 Bits (En este caso Slackware64 15.0) : mount --rbind /proc "$OBJETIVO/proc" ; \ mount --make-rslave "$OBJETIVO/proc" ; \ mount --rbind /sys "$OBJETIVO/sys" ; \ mount --make-rslave "$OBJETIVO/sys" ; \ mount --rbind /dev "$OBJETIVO/dev" ; \ mount --make-rslave "$OBJETIVO/dev" ; \ mount --rbind /dev/pts "$OBJETIVO/dev/pts" ; \ mount --make-rslave "$OBJETIVO/dev/pts" ; \ mount --rbind /run "$OBJETIVO/run" ; \ mount --make-rslave "$OBJETIVO/run" ; \ mount --rbind /tmp "$OBJETIVO/tmp" ; \ mount --make-rslave "$OBJETIVO/tmp" ; \ mount --rbind /var/run/dbus "$OBJETIVO/var/run/dbus" ; \ mount --make-rslave "$OBJETIVO/var/run/dbus" ; \ mount --rbind /var/lib/dbus "$OBJETIVO/var/lib/dbus" ; \ mount --make-rslave "$OBJETIVO/var/lib/dbus" ; \ mount --rbind /lib/modules "$OBJETIVO/lib/modules" ; \ mount --make-rslave "$OBJETIVO/lib/modules" ; \ mount --bind /etc/fstab "$OBJETIVO/etc/fstab" ; \ mount --bind /etc/hostname "$OBJETIVO/etc/hostname" ; \ mount --bind /etc/hosts "$OBJETIVO/etc/hosts" ; \ mount --bind /etc/resolv.conf "$OBJETIVO/etc/resolv.conf" ; \ $(Xephyr -screen 1070x887 -ac -br -reset -terminate :1.0 \ +extension Composite \ +extension DAMAGE \ +extension DOUBLE-BUFFER \ +extension DPMS \ +extension GLX \ +extension MIT-SCREEN-SAVER \ +extension MIT-SHM \ +extension RANDR \ +extension RENDER \ +extension X-Resource \ +extension XFIXES \ +extension XTEST \ +extension XVideo \ +iglx \ 2>/dev/null &) export xerphid=$(pidof "Xephyr") cat /dev/null) EOF chroot "$OBJETIVO" /bin/bash -l /dev/null &) EOT #Esperar que Xephyr sea cerrado para desmontar particiones : tail --pid="$xerphid" -f /dev/null sleep 120 umount "$OBJETIVO/etc/resolv.conf" umount "$OBJETIVO/etc/hosts" umount "$OBJETIVO/etc/hostname" umount "$OBJETIVO/etc/fstab" umount "$OBJETIVO/lib/modules" umount "$OBJETIVO/var/lib/dbus" umount "$OBJETIVO/var/run/dbus" umount "$OBJETIVO/tmp" umount -l "$OBJETIVO/run" umount "$OBJETIVO/dev/pts" umount -l "$OBJETIVO/dev" umount -l "$OBJETIVO/sys" umount "$OBJETIVO/proc" umount -l /dev/ndb0p1 qemu-nbd --disconnect /dev/nbd0 1>/dev/null sleep 7 mount -a 2>/dev/null } function desmontar(){ # Desmontar umount "$OBJETIVO/etc/resolv.conf" umount "$OBJETIVO/etc/hosts" umount "$OBJETIVO/etc/hostname" umount "$OBJETIVO/etc/fstab" umount "$OBJETIVO/lib/modules" umount "$OBJETIVO/var/lib/dbus" umount "$OBJETIVO/var/run/dbus" umount "$OBJETIVO/tmp" #umount -l "$OBJETIVO/run" 2>/dev/null umount "$OBJETIVO/run" umount "$OBJETIVO/dev/pts" #umount -l "$OBJETIVO/dev" 2>/dev/null umount "$OBJETIVO/dev" #umount -l "$OBJETIVO/sys" 2>/dev/null umount "$OBJETIVO/sys" umount "$OBJETIVO/proc" #umount -l /dev/ndb0p1 2>/dev/null umount -l /dev/ndb0p1 2>/dev/null qemu-nbd --disconnect /dev/nbd0 1>/dev/null sleep 7 mount -a 2>/dev/null } #Este guión necesita ser ejecutado como SuperUsuario #o en su defecto con permisos administrativos suficientes #Para montar / desmontar particiones. if [ "$(whoami)" != root ]; then echo echo echo 'Por favor ejecuta este guion como SuperUsuario (root)' echo echo 'Utilize este guión bajo su Propio Riesgro' echo 'El Autor , o sea yo , no me hago responsable' echo 'de las consecuencias imprevistas que puedan' echo 'acontecer en tu sistema operativo' echo else # Proceder en caso de tener los permisos suficientes para montar/desmontar particiones : #Si el usuario no pasa ningun parametro iniciar directamente en "Xephyr" #En la interfaz de linea de comandos (ILC / CLI ) indicar como se puede usar este guion if [ -z "$1" ]; then echo MensajeBase echo xephyr fi #Guion : Aqui se ha definido como se utilizara este guion correctamente para montar o desmontar la particion Objetivo #Entrada : Cualquier palabra pasada por el parametro $1 sera convertida en minusculas Entrada=$(echo "$1" | tr -s '[:upper:]' '[:lower:]') if [ "$Entrada" == "montar" ]; then montar fi if [ "$Entrada" == "xephyr" ]; then xephyr fi if [ "$Entrada" == "desmontar" ]; then desmontar fi #Finalizar la condicion global de requerir usar el SuperUsuario o en su defectos persmisos administrativos #Para poder (des)montar particiones : fi The problem is when i indicate on the Xephyr window, and i wait around 5 mins for all process finish for close the Xephyr window manully because never gone, i can't umount the partions, because are still busy by "jbd2/nbd0p1-8", and neither i can force the kernel module "nbd" unload because is on use.

Is there any way to start a **XDMCP** session, say with **Xephyr** in **LightDM**, locally through **Unix Sockets** instead of **IP**? For performance I was wondering if, somehow, I can avoid any network stack working with **Xephyr** and the **XDMCP** server in the same machine.

With swaywm I'm almost multiseating (two people simultaneously using the same computer) with two keyboards, two mice and **one** GPU with two outputs. At the start of the sway session, one nested X session is opened with Xephyr querying the localhosts XDMCP server (enabled in lightdm) In short, these are the commands executed: swaymsg "input abc:xyz:mouse map_to_output VGA-1" swaymsg "seat seat1 attach abc:xyz:keyboard" swaymsg "seat seat1 attach abc:xyz:mouse" swaymsg "seat seat1 shortcuts_inhibitor enable" Xephyr -query 127.0.0.1 -glamor -screen 1280x720 -noreset -no-host-grab -name Xephyr1 :1 & sleep 3 swaymsg "[instance=Xephyr1] move window to output VGA-1" swaymsg "[instance=Xephyr1] focus" swaymsg "floating disable" Xephyr successfully opens a new session, then it's moved to the proper monitor and one of the mice moves only there, and that's it. Now, how could I capture the keyboard and mouse keypresses from the input devices attached to "seat1" only to that window/container regardless of focus? Xephyr -keybd/-mouse driver settings don't work at all, neither does -seat. I know how to multiseat with multiple GPUs and loginctl defining seats, but my goal is to multiseat with one GPU in any recent Linux distribution and not in old, patched ones.

Just to make it easier to mount my Slackware 14.2 Installation, I put it on another partition (it's 32 Bits 100% real native). I can start xfce4-session like root user (but that is not the thing I need) : ![ch"root"]("]https://i.postimg.cc/SRJjVfm5/Xephyr-ch-ROOT.png) I need to know if someone can help me with the follow things 1 - Redirect audio to host, because  2 - Is possible use 3D,DRI with Nvidia ? I saw something on a Gentoo forum, but I don't understand it)  3 - Hide some commands and/or outputs from my script : The lines are :

local being added to access control list

export DISPLAY=localhost:1 2>/dev/null

exit

and when I close the Xephyr window, this shows up afterwards:

-su: línea 3: $'\E[01mHP': no se encontró la orden

 My script "slack32-chroot" content :

#!/usr/bin/env bash

echo '
Autor ----------------> Inukaze ( Venezuela )
Sitio ----------------> https://goo.gl/ij6WqW 
Correo-E -------------> bloginukaze@gmail.com
Licencia -------------> GPL 2
'
#Establecer mediante la variable "$OBJETIVO" 
#La particion con una distribucion a la cual se accedera mediante chroot
export OBJETIVO="/media/Slack32"

#Prevenir que se autoejecuten las funciones que se definiran despues
unset montar
unset desmontar
unset MensajeBase

#Establecer y definir funciones :
function MensajeBase()
{
echo -e "\nLa forma correcta de utilizar este guion es :\n$0 «montar» , «montar_xephyr» ó «desmontar», Por ejemplo : \n"
echo -e "$0 montar"
echo -e "$0 montar_xephyr"
echo -e "$0 desmontar\n"
}

function montar(){
#Preparar acceso para programas de entorno grafico :
export DISPLAY=:0.0 2>/dev/null
xhost + local 2>/dev/null

#Montar todo de una vez para una distro de 32 Bits (En este caso Slackware32 14.2) : 
mount --rbind /proc							"$OBJETIVO/proc"						; \
mount --make-rslave							"$OBJETIVO/proc"						; \
mount --rbind /sys								"$OBJETIVO/sys"							; \
mount --make-rslave							"$OBJETIVO/sys"							; \
mount --rbind /dev							"$OBJETIVO/dev"							; \
mount --make-rslave							"$OBJETIVO/dev"							; \
mount --rbind /run								"$OBJETIVO/run"							; \
mount --make-rslave							"$OBJETIVO/run"							; \
mount --rbind /tmp							"$OBJETIVO/tmp"							; \
mount --make-rslave							"$OBJETIVO/tmp"							; \
mount --bind /etc/fstab						"$OBJETIVO/etc/fstab"					; \
mount --bind /etc/hostname			"$OBJETIVO/etc/hostname"		; \
mount --bind /etc/hosts						"$OBJETIVO/etc/hosts"				; \
mount --bind /etc/resolv.conf			"$OBJETIVO/etc/resolv.conf"		; \

cat /dev/null
EOF

linux32 chroot									"$OBJETIVO"	/bin/bash -l				; \
umount -l											"$OBJETIVO"									; \
mount -a 2>/dev/null
}


function xephyr(){
#Copiar archivo de autorizacion X.Org :
rm -f "$OBJETIVO/home/inukaze/.Xauthority"
rm -f "$OBJETIVO/root/.Xauthority"
cp -f "/home/inukaze/.Xauthority" "$OBJETIVO/root/.Xauthority"
cp -f "/home/inukaze/.Xauthority" "$OBJETIVO/home/inukaze/.Xauthority"
chown inukaze:users "$OBJETIVO/home/inukaze/.Xauthority"

if [ ! -f "$OBJETIVO/etc/X11/Xwrapper.config" ] ; then
# Prevenir el error « /usr/libexec/Xorg.wrap: Only console users are allowed to run the X server »
echo '# Xwrapper.config (Debian X Window System server wrapper configuration file)
#
# This file was generated by the post-installation script of the x11-common
# package using values from the debconf database.
#
# See the Xwrapper.config(5) manual page for more information.
#
# This file is automatically updated on upgrades of the x11-common package
# *only* if it has not been modified since the last upgrade of that package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command as root:
#   dpkg-reconfigure x11-common
#allowed_users=console
allowed_users=anybody' | tee "$OBJETIVO/etc/X11/Xwrapper.config"
fi

#Preparar acceso para programas de entorno grafico :
export DISPLAY=:0.0 2>/dev/null
xhost + local 2>/dev/null

#Montar todo de una vez para una distro de 32 Bits (En este caso Slackware32 14.2) : 
mount --rbind /proc							"$OBJETIVO/proc"						; \
mount --make-rslave							"$OBJETIVO/proc"						; \
mount --rbind /sys								"$OBJETIVO/sys"							; \
mount --make-rslave							"$OBJETIVO/sys"							; \
mount --rbind /dev							"$OBJETIVO/dev"							; \
mount --make-rslave							"$OBJETIVO/dev"							; \
mount --rbind /run								"$OBJETIVO/run"							; \
mount --make-rslave							"$OBJETIVO/run"							; \
mount --rbind /tmp							"$OBJETIVO/tmp"							; \
mount --make-rslave							"$OBJETIVO/tmp"							; \
mount --bind /etc/fstab						"$OBJETIVO/etc/fstab"					; \
mount --bind /etc/hostname			"$OBJETIVO/etc/hostname"		; \
mount --bind /etc/hosts						"$OBJETIVO/etc/hosts"				; \
mount --bind /etc/resolv.conf			"$OBJETIVO/etc/resolv.conf"		; \

cat /dev/null
EOF

linux32 chroot									"$OBJETIVO"	/bin/bash -l		/dev/null &)
$(export DISPLAY=:1.0)
$(DISPLAY=:1 /usr/bin/xfce4-session -- :1 2>/dev/null)
EOT

umount -l											"$OBJETIVO"									; \
mount -a 2>/dev/null
}

function desmontar(){
# Desmontar
umount -l			"$OBJETIVO"							; \
mount -a 2>/dev/null
}


#Este guión necesita ser ejecutado como SuperUsuario
#o en su defecto con permisos administrativos suficientes
#Para montar / desmontar particiones.
if [ "$(whoami)" != root ]; then

	echo
	echo
	echo 'Por favor ejecuta este guion como SuperUsuario (root)'
	echo
	echo 'Utilize este guión bajo su Propio Riesgro'
	echo 'El Autor , o sea yo , no me hago responsable'
	echo 'de las consecuencias imprevistas que puedan'
	echo 'acontecer en tu sistema operativo'
	echo
else
# Proceder en caso de tener los permisos suficientes para montar/desmontar particiones :

#Si el usuario no pasa ningun parametro indicar como se usa este guion
			if [ -z "$1" ]; then
					MensajeBase
			fi

#Guion : Aqui se ha definido como se utilizara este guion correctamente para montar o desmontar la particion Objetivo
#Entrada : Cualquier palabra pasada por el parametro $1 sera convertida en minusculas
Entrada=$(echo "$1" | tr -s  '[:upper:]'  '[:lower:]')

			if [ "$Entrada" == "montar" ]; then
					montar
			fi

			if [ "$Entrada" == "xephyr" ]; then
					xephyr
			fi

			if [ "$Entrada" == "desmontar" ]; then
					desmontar
			fi

#Finalizar la condicion globar de requerir usar el SuperUsuario o en su defectos persmisos administrativos
#Para poder (des)montar particiones :
fi

#Finalizar este guion sin problemas :
exit 0 2>/dev/null

This is a copy from [LinuxQuestions.org](https://www.linuxquestions.org/questions/showthread.php?p=6309616#post6309616)

I am running GNOME Shell under Wayland and I would like to debug extensions in a nested session so that I don't have to restart the compositor, how can I do that?

How to replay Chaosreader X11.replay session? I tried this:

Xephyr -br -ac -noreset :1
DISPLAY=:1 ./session_0001.X11.replay

But got

ERROR42: Can't connect to X11 daemon on 127.0.0.1:6001 at ./session_0001.X11.replay line 57.

I'm curious as to which of the two is the more tested and generally approved way of sandboxing X11. Both are available in my distributions official repository, but I don't know which one I should choose. Any suggestions?

when I open new openbox session in Xephyr, the screen goes blank after 10 minutes of inactivity. How can I disable this ? I tried this command: xset -dpms s off but get following error: server does not have extension for -dpms option

I run firefox with the following command:

firejail --x11=xephy firefox

----- The command usually opens a firefox window (800x600) that fills the xephyr window (800x600). In this case, the following problems occur. Problems: - When I click on the hamburger menu, it shows the menu briefly appears and then quickly disappears. - When I type "alt" the menu bar at top appears. Then when I type f, the file menu briefly appears then quickly disappears. ----- However, after I run the command, I can intentionally kill xephyr (by pressing alt-f4). When I run the command again, firefox starts in safe-mode. The firefox in safe-mode would open a window that is smaller than 800x600. In this case, the problem disappears ----- Somehow setting the height and width of the firefox command as below doesn't solve the problem.

firejail --x11=xephy firefox -width=700 -height=500

----- The window environment is debian 10 + jwm + xorg. I start it by startx -- -nolisten local.

The goal is to launch Xephyr in a script. The most popular approach is this: Xephyr :4 & sleep 1 # or sleep 2 launch_your_program_here Let's see what happens here. First, unfortunately, Xephyr cannot daemonize itself, so we have to launch it asynchonously (&). Then we don't know when it's initialized, so we give it 1-2 seconds to initialize. This feels hacky. How to do it faster and more reliably?