[Bug]: Only a Black screen and a cursor show up when I start the session

[0x6e7a6f]

What happened?

I got this issue on both Arch Linux and Debian Sid.
When I start singularity in first place on the computer, I got most of the time a black screen with a cursor and the ability to right click. It open a window with the tab "reconfigure", "terminal", "exit" (only "exit" is working). I got few error :

• In desktop.log, It seems that singularity-desktop is restarting in loop :
  singularity-desktop exited 1, restarting in 2s...

• In polkit.log :
  WARNING **: : agent.vala:51: Failed to register for session 5: An object is already exported for the interface org.freedesktop.PolicyKit1.AuthenticationAgent at /dev/sinty/PolicyKit1/AuthenticationAgent

• In singularity-desktop.log :
  Gtk-WARNING **: : Failed to open display

Steps to reproduce

In general It happening when I open it in first place on the computer. Singularity open normally if I have another Desktop open beside, after few try It working fine. So I wondering if It's not related to wayland socket management or something else, but that's a bit beyond my knowledge. I will continue to investigate on my side (at my level) to try to give further information.

Expected behavior

Open normally the Desktop

Component / area

Other / not sure

How are you running Singularity?

Inside the Singularity session, started with singularity-labwc-session from a TTY

Distribution

Arch Linux ~ Debian Sid

How did you install it?

Built from source

System components

## Singularity report

- Singularity Desktop: 0.1.6
- OS: Arch Linux
- Kernel: 7.0.11-arch1-1
- Graphics: AMD Graphics
- Processor: AMD Ryzen 7 9700X 8-Core Processor
- Memory: 30.5 GiB

## Singularity system components

| Component | Version | License |
|-----------|---------|---------|
| labwc | 0.9.5 | GPL-2.0-only |
| wlroots | 0.20.1 | MIT |
| Wayland | 0.25.0 | MIT |
| Xwayland | 24.1.12 | MIT |
| Vulkan loader | 1.4.350 | Apache-2.0 |
| libinput | 10.13.0 | MIT |
| libxkbcommon | 0.13.2 | MIT |
| pixman | 0.46.4 | MIT |
| gtk4-layer-shell | 1.3.0 | MIT |
| libdecor | 0.200.5 | MIT |
| libliftoff | 0.5.0 | MIT |
| GTK | 4.22.4 | LGPL-2.1-or-later |
| GLib | 2.88.1 | LGPL-2.1-or-later |
| Pango | 1.57.1 | LGPL-2.1-or-later |
| Cairo | 1.18.4 | LGPL-2.1-or-later |
| gdk-pixbuf | 0.4400.6 | LGPL-2.1-or-later |
| VTE | installed | LGPL-3.0-or-later |
| GtkSourceView | 0.0.0 | LGPL-2.1-or-later |
| libpeas | 0.200.1 | LGPL-2.1-or-later |
| json-glib | 1.10.8 | LGPL-2.1-or-later |
| libgee | 2.6.1 | LGPL-2.1-or-later |
| libsoup | 0.7.4 | LGPL-2.0-or-later |
| D-Bus | 1.16.2 | AFL-2.1 OR GPL-2.0+ |
| PipeWire | 1.6.6 | MIT |
| WirePlumber | 0.5.14 | MIT |
| xdg-desktop-portal | Not installed | LGPL-2.1-or-later |
| polkit | pkaction version 127 | LGPL-2.0-or-later |
| NetworkManager | 1.56.1-1 | GPL-2.0-or-later |
| BlueZ | Not installed | GPL-2.0-or-later |
| Wayland protocols | 11 / 11 active | MIT OR Singularity |

### Capabilities

- **labwc**
  - ✅ XWayland support
  - ✅ SVG icon rendering (rsvg)
  - ✅ Translations (nls)
  - ✅ Desktop/icon lookup (libsfdo)
- **wlroots**
  - ✅ DRM / KMS device
  - ✅ GPU render node
- **Xwayland**
  - ✅ X11 display socket
- **Vulkan loader**
  - ✅ Vulkan ICD installed
  - ✅ GPU render node
- **Wayland protocols**
  - ✅ Panel and dock surfaces (layer-shell)
  - ✅ Taskbar and dock (foreign-toplevel management)
  - ✅ Workspaces
  - ✅ Window previews
  - ✅ Tiling and snapping
  - ✅ Display configuration
  - ✅ Lock screen
  - ✅ Screenshots
  - ✅ Screen casting
  - ✅ Background blur
  - ✅ Night light (gamma control)

Logs / output

Not on a working state :
➜  ~ cat ~/.local/state/singularity/desktop.log.1
[Thu Jun 11 21:39:37 CEST 2026] ENV: WAYLAND_DISPLAY=wayland-0 DISPLAY=:1 XDG_RUNTIME_DIR=/run/user/1000 XDG_CURRENT_DESKTOP=Singularity
[Thu Jun 11 21:40:28 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:30 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:32 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:34 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:36 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:38 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:40 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:42 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:44 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:46 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:48 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:50 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:52 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:54 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:56 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:40:58 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:00 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:02 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:04 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:06 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:08 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:10 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:12 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:14 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:16 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:18 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:20 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:23 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:25 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:27 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:29 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:31 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:33 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:35 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:37 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:39 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:41 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:43 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:45 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:47 CEST 2026] singularity-desktop exited 1, restarting in 2s...
[Thu Jun 11 21:41:49 CEST 2026] singularity-desktop exited 1, restarting in 2s...

➜  ~ cat ~/.local/state/singularity/polkit.log

** (singularity-polkit-agent:1053): WARNING **: 21:39:38.199: agent.vala:51: Failed to register for session 4: An object is already exported for the interface org.freedesktop.PolicyKit1.AuthenticationAgent at /dev/sinty/PolicyKit1/AuthenticationAgent

➜  ~ cat ~/.local/state/singularity/singularity-desktop.log.old

(singularity-desktop:8385): Gtk-WARNING **: 21:53:27.570: Failed to open display


Working state :
cat ~/.local/state/singularity/desktop.log
[Thu Jun 11 21:53:28 CEST 2026] ENV: WAYLAND_DISPLAY=wayland-0 DISPLAY=:2 XDG_RUNTIME_DIR=/run/user/1000 XDG_CURRENT_DESKTOP=Singularity

cat ~/.local/state/singularity/singularity-desktop.log

** (singularity-desktop:8477): WARNING **: 21:53:29.034: main.vala:1315: cursor theme: failed to merge Xcursor resources: Failed to execute child process “xrdb” (No such file or directory)

** (singularity-desktop:8477): WARNING **: 21:53:29.035: main.vala:1230: x font settings: xrdb merge failed: Failed to execute child process “xrdb” (No such file or directory)

** (singularity-desktop:8477): WARNING **: 21:53:29.157: main.vala:160: Lost name org.freedesktop.Notifications
** Message: 21:53:29.186: audio_manager.vala:92: AudioManager: PulseAudio Context READY
** Message: 21:53:29.187: nm_wrapper.vala:44: NetworkManager Client initialized

** (singularity-desktop:8477): WARNING **: 21:53:29.187: nm_wrapper.vala:115: No WiFi device found!
** Message: 21:53:29.254: shortcut_manager.vala:301: ShortcutManager: rc.xml unchanged, skipping reload
** Message: 21:53:29.285: wallpaper_manager.vala:126: Wallpaper loaded: /opt/local/share/backgrounds/singularity/default.png
** Message: 21:53:29.286: display_manager.vala:336: DisplayManager: loaded saved config from /home/enzo/.config/singularity/displays.json

** (singularity-desktop:8477): WARNING **: 21:53:29.287: shortcut_manager.vala:386: xsettingsd launch: Failed to execute child process “xsettingsd” (No such file or directory)

** (singularity-desktop:8477): WARNING **: 21:53:29.287: file_search_provider.vala:24: Failed to connect to Tracker: The name is not activatable. File search might be disabled.
/bin/sh: line 1: xsettingsd: command not found

** (singularity-desktop:8477): WARNING **: 21:53:29.663: tray-icons.vala:124: TrayIcons: lost StatusNotifierWatcher name
Gtk-Message: 21:53:29.830: Failed to load module "appmenu-gtk-module"

** (localsend:8557): CRITICAL **: 21:53:29.966: Failed to read XDG desktop portal settings: GDBus.Error:org.freedesktop.portal.Error.NotFound: Requested setting not found

** (localsend:8557): CRITICAL **: 21:53:29.966: Failed to read XDG desktop portal settings: GDBus.Error:org.freedesktop.portal.Error.NotFound: Requested setting not found

** (localsend:8557): CRITICAL **: 21:53:29.966: Failed to read XDG desktop portal settings: GDBus.Error:org.freedesktop.portal.Error.NotFound: Requested setting not found

** (localsend:8557): CRITICAL **: 21:53:29.966: Failed to read XDG desktop portal settings: GDBus.Error:org.freedesktop.portal.Error.NotFound: Requested setting not found
flutter: dynamic_color: Accent color detected.
flutter: 2026-06-11 21:53:29.994167    [INFO] [PersistenceService] Existing version: 2
flutter: 2026-06-11 21:53:29.996572    [INFO] [TrayHelper] Using "assets/img/logo-32-white.png" as path of system tray icon

(localsend:8557): libayatana-appindicator-WARNING **: 21:53:29.997: libayatana-appindicator is deprecated. Please use libayatana-appindicator-glib in newly written code.
flutter: 2026-06-11 21:53:30.012078    [INFO] [ChildIsolateMain] Child isolate is ready: HttpScanDiscoveryIsolate (logLevel: INFO)
flutter: 2026-06-11 21:53:30.012101    [INFO] [ChildIsolateMain] Child isolate is ready: HttpTargetDiscoveryIsolate (logLevel: INFO)
flutter: 2026-06-11 21:53:30.012245    [INFO] [ChildIsolateMain] Child isolate is ready: MulticastDiscoveryIsolate (logLevel: INFO)
flutter: 2026-06-11 21:53:30.012264    [INFO] [ChildIsolateMain] Child isolate is ready: HttpUploadIsolate (logLevel: INFO)
flutter: 2026-06-11 21:53:30.012277    [INFO] [ChildIsolateMain] Child isolate is ready: HttpUploadIsolate (logLevel: INFO)
flutter: 2026-06-11 21:53:30.012431    [INFO] [Multicast] Bind UDP multicast port (ip: [192.168.1.130, 2a01:e0a:5bc:77a0:f0d9:f70f:ef7c:dc4a], group: 224.0.0.167, port: 53317)
flutter: 2026-06-11 21:53:30.079144    [INFO] [Server] Starting server...
flutter: 2026-06-11 21:53:30.079640    [INFO] [Server] Server started. (Port: 53317, HTTPS only)
flutter: 2026-06-11 21:53:30.081639    [INFO] [NetworkInfo] Network state: [192.168.1.130]
flutter: 2026-06-11 21:53:30.083067    [INFO] [NetworkInfo] Network state: [192.168.1.130]
flutter: 2026-06-11 21:53:30.113246    [INFO] [Multicast] Announce via UDP
flutter: 2026-06-11 21:53:30.614274    [INFO] [Multicast] Announce via UDP
flutter: 2026-06-11 21:53:32.615301    [INFO] [Multicast] Announce via UDP
Gtk-Message: 21:53:33.097: Failed to load module "appmenu-gtk-module"
Command line interface is not enabled. Please turn it on in Settings > General > Advanced.
** Message: 21:53:34.569: bluetooth_manager.vala:90: BluetoothManager: Connected to org.bluez ObjectManager

** (singularity-desktop:8477): WARNING **: 21:53:34.569: bluetooth_manager.vala:108: Failed to connect to BlueZ: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name is not activatable

** (singularity-desktop:8477): CRITICAL **: 21:53:34.569: singularity_system_view_get_profile_icon_with_extreme: assertion 'profile != NULL' failed

** (singularity-desktop:8477): CRITICAL **: 21:53:34.569: singularity_system_view_format_profile_name_with_extreme: assertion 'profile != NULL' failed

** (singularity-desktop:8477): CRITICAL **: 21:53:34.569: singularity_system_view_get_profile_state_with_extreme: assertion 'profile != NULL' failed

** (singularity-desktop:8477): WARNING **: 21:53:34.569: bluetooth_manager.vala:224: Bluetooth agent registration failed: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name is not activatable
Gtk-Message: 21:53:43.083: Failed to load module "appmenu-gtk-module"
Command line interface is not enabled. Please turn it on in Settings > General > Advanced.

** (singularity-desktop:8477): WARNING **: 21:53:44.588: dock_dbus_service.vala:89: DockDBusService register_object failed: An object is already exported for the interface dev.sinty.Dock at /dev/sinty/Dock

** (singularity-desktop:8477): WARNING **: 21:53:44.588: dock_dbus_service.vala:94: DockDBusService: name lost

** (singularity-desktop:8477): WARNING **: 21:55:39.180: dock_dbus_service.vala:89: DockDBusService register_object failed: An object is already exported for the interface dev.sinty.Dock at /dev/sinty/Dock

** (singularity-desktop:8477): WARNING **: 21:55:39.203: dock_dbus_service.vala:94: DockDBusService: name lost

(singularity-edit:9304): GtkSourceView-WARNING **: 21:55:43.801: No match style defined nor 'search-match' style available.

(singularity-edit:9304): Gtk-WARNING **: 21:55:43.801: Theme parser error: <data>:1:18-27: Expected a number

** (singularity-desktop:8477): WARNING **: 21:55:52.136: app_system.vala:1085: AppSystem: FAILED to resolve AppInfo for 'singularity-files'. Dock icon may be missing or generic.

(singularity-desktop:8477): Gdk-CRITICAL **: 21:55:52.168: gdk_wayland_toplevel_set_a11y_properties: assertion 'GDK_IS_WAYLAND_TOPLEVEL (toplevel)' failed

** (singularity-desktop:8477): WARNING **: 21:55:58.812: dock_dbus_service.vala:89: DockDBusService register_object failed: An object is already exported for the interface dev.sinty.Dock at /dev/sinty/Dock

** (singularity-desktop:8477): WARNING **: 21:55:58.812: dock_dbus_service.vala:94: DockDBusService: name lost

** (singularity-desktop:8477): WARNING **: 21:56:11.049: dock_dbus_service.vala:89: DockDBusService register_object failed: An object is already exported for the interface dev.sinty.Dock at /dev/sinty/Dock

** (singularity-desktop:8477): WARNING **: 21:56:11.060: dock_dbus_service.vala:94: DockDBusService: name lost

** (singularity-desktop:8477): WARNING **: 21:56:12.832: app_system.vala:1085: AppSystem: FAILED to resolve AppInfo for 'singularity-files'. Dock icon may be missing or generic.

** (singularity-desktop:8477): WARNING **: 21:56:20.957: dock_dbus_service.vala:89: DockDBusService register_object failed: An object is already exported for the interface dev.sinty.Dock at /dev/sinty/Dock

** (singularity-desktop:8477): WARNING **: 21:56:20.957: dock_dbus_service.vala:94: DockDBusService: name lost

Before submitting

• I have searched the existing issues
• I have given a specific title and filled every field above

[0x6e7a6f]

The issue is reproducible both with labwc and via singularity-labwc-session, so it does not seem related to the launcher. Reproducible in both from TTY (no desktop session running) and from existing session (COSMIC in my case).

So I understand something, the start is like "delayed" of approximatly 45 seconds :

• Black screen and cursor appears immediately after launch (my agent say "so DRM/KMS is active")
• Screen remains in this state for around 45 seconds
• After this delay, the desktop appears and works normally

I tried multiple wlroots configurations without any state change:
WLR_RENDERER=gles2 WLR_RENDERER=pixman WLR_DRM_NO_ATOMIC=1 WLR_DRM_NO_MODIFIERS=1 WLR_NO_HARDWARE_CURSORS=1 WLR_DRM_DEVICES=/dev/dri/card1

What to know, I have an Nvidia card but too an intagrated AMD GPU. May be not important in that case because I experience the same issue on Debian Sid, running on a laptop with a totally different configuration.

I have made this to have few logs at startup :
WAYLAND_DEBUG=server WLR_DEBUG=1 ./singularity-labwc-session 2>&1 | tee ~/labwc-debug.log

I have few weird thing in the logs :
[ERROR] [backend/drm/drm.c:1385] connector HDMI-A-1: Failed to disable CRTC 198 [ERROR] [backend/drm/drm.c:1385] connector DP-1: Failed to disable CRTC 390 [...] [ERROR] [../src/view.c:491] invalid output set for view [ERROR] [../src/view.c:827] view has no output, not centering [ERROR] [../src/view.c:1734] cannot save last placement in usable [ERROR] [../src/view.c:1762] view has no last placement info [...] Found 2 GPUs Initializing DRM backend for /dev/dri/card1 (nvidia-drm) Initializing DRM backend for /dev/dri/card0 (amdgpu) Creating multi-GPU renderer [...] Failed to pick output format Failed to pick cursor format Failed to render cursor buffer Falling back to software cursor
These errors occur immediately after startup and persist until the desktop finally works.

And when It work, It show :
[DEBUG] [../src/action.c:1643] Handling action 17: ShowMenu -> zwlr_output_configuration_v1#3.succeeded() -> wl_surface#47.enter(wl_output#31) -> wl_surface#60.enter(wl_output#34)

Anyway, I share the 16k lines log.

If anyone having this issues or having clues to fix it, do not hesitate !

labwc-debug.log

[0x6e7a6f]

I think I may have identified a potential issue related to the xdg-desktop-portal stack. But not sure at all. I still try to figure out what is wrong. I found things but without a real fix, I can't be sure.

Before installing Singularity Desktop, I never experienced this problem. After installing it, I started seeing intermittent startup issues after login. GTK applications (for example GNOME Calculator and my web browser) fail to launch or take a very long time to appear (a bit like Singularity).

While investigating, I noticed portal-related timeouts. For example, launching GNOME Calculator show warnings such as :

Cannot get portal org.freedesktop.host.portal.Registry version: Timeout was reached
Cannot get portal org.freedesktop.portal.Settings version: Timeout was reached

I also checked the portal service immediately after a login and found that xdg-desktop-portal was still stuck in the "activating" state :

systemctl --user status xdg-desktop-portal

Active: activating (start)`

At the same time, I tried portal requests, and It were timing out :

busctl --user call org.freedesktop.portal.Desktop \
  /org/freedesktop/portal/desktop \
  org.freedesktop.portal.Settings \
  Read ss org.freedesktop.appearance color-scheme

Call failed: Connection timed out

However, after restarting the portal stack manually :

systemctl --user unmask xdg-desktop-portal
systemctl --user unmask xdg-desktop-portal-gtk
systemctl --user unmask xdg-desktop-portal-gnome
systemctl --user restart xdg-desktop-portal

the portal immediately became responsive :

busctl --user call org.freedesktop.portal.Desktop \
  /org/freedesktop/portal/desktop \
  org.freedesktop.portal.Settings \
  Read ss org.freedesktop.appearance color-scheme

v v u 1

and all GTK applications that were waiting to start appeared instantly.

I can still reproduce this after a logout/login cycle. Today, after logging into GNOME, several GTK applications would not launch correctly until I restarted xdg-desktop-portal as shown above.

This may indicate a startup race condition or interaction between Singularity's portal backend and the existing portal backends. I cannot confirm the root cause yet, but the issue only started after installing Singularity Desktop, and manually restarting xdg-desktop-portal consistently resolves it. But it may be another wrong direction

If anyone have experienced this issue or have any clues, feel free to share it !

[mirkobrombin]

I fixed this a commit ago, can you test please?

[0x6e7a6f]

I fixed this a commit ago, can you test please?

Hello Mirko :)

I just rebuild the desktop. I still encounter the issue when singularity-keyring.service is unmask. I have similar logs.

I am around if you want me to execute commands.

[mirkobrombin]

I am looking into this, I'll tell you if I need any test.