X11 + dwm: Screenshot portal times out when GTK portal backend does not provide Screenshot interface; legacy X11 fallback works

[ruhagen]

Flameshot Version

Flameshot v14.0.0 ()
Compiled with Qt 6.11.1

Installation Type

Linux, MacOS, or Windows Package manager (apt, pacman, eopkg, choco, brew, ...)

Operating System type and version

Arch Linux (7.0.11-arch1-1)

Description

Hi team,

I’m running into an issue with Flameshot on a minimal X11 setup. I understand that the root cause may not be directly inside Flameshot, but I think Flameshot could possibly handle this case better or provide a clearer diagnostic/fallback.

Environment:

• OS: Arch Linux
• Window manager: dwm
• Session type: X11, started via startx
• Shell: zsh
• Flameshot: installed from pacman
• xdg-desktop-portal: 1.22.0-1
• xdg-desktop-portal-gtk: 1.15.3-1
• DBus session bus: unix:path=/run/user/1000/bus
• Portal frontend service: running
• GTK portal backend service: running

The original error was:

flameshot: error: Could not locate the `org.freedesktop.portal.Desktop` service
flameshot: error: Unable to capture screen
flameshot: info: Screenshot aborted.

After fixing my dwm/startx session setup by adding a user target for the graphical session and starting it from xinitrc, the portal frontend and GTK backend started correctly:

org.freedesktop.portal.Desktop
org.freedesktop.impl.portal.desktop.gtk

Both services are active:

xdg-desktop-portal.service - active (running)
xdg-desktop-portal-gtk.service - active (running)

However, flameshot gui still fails with:

flameshot: error: Screenshot portal timed out after 30 seconds
flameshot: error: Unable to capture screen
flameshot: info: Screenshot aborted.

After checking the installed GTK portal backend file:

grep -nE 'Interfaces|Screenshot' /usr/share/xdg-desktop-portal/portals/gtk.portal

I get:

Interfaces=org.freedesktop.impl.portal.FileChooser;org.freedesktop.impl.portal.AppChooser;org.freedesktop.impl.portal.Print;org.freedesktop.impl.portal.Notification;org.freedesktop.impl.portal.Inhibit;org.freedesktop.impl.portal.Access;org.freedesktop.impl.portal.Account;org.freedesktop.impl.portal.Email;org.freedesktop.impl.portal.DynamicLauncher;org.freedesktop.impl.portal.Lockdown;org.freedesktop.impl.portal.Settings;

There is no:

org.freedesktop.impl.portal.Screenshot

Also:

busctl --user introspect org.freedesktop.impl.portal.desktop.gtk /org/freedesktop/portal/desktop | grep -i Screenshot

returns nothing.

So the portal frontend is present and the GTK backend is running, but there is no backend implementation for the Screenshot interface in this setup. Because of that, Flameshot waits for the screenshot portal and eventually times out.

The workaround is to enable:

useX11LegacyScreenshot=true

Then flameshot gui works correctly on X11.

My request:

Could Flameshot detect this situation more gracefully?

For example:

1. If running under X11, and the portal frontend exists but no active backend provides org.freedesktop.impl.portal.Screenshot, automatically fall back to the legacy X11 screenshot method.
2. Or show a clearer error message, something like:
   “The current xdg-desktop-portal backend does not implement the Screenshot interface. On X11 minimal window managers, enable legacy X11 screenshot method.”
3. Optionally avoid waiting the full 30 seconds if the selected portal backend clearly does not expose the Screenshot interface.

I realize that implementing Screenshot support in the GTK portal backend may belong to xdg-desktop-portal-gtk rather than Flameshot. But since Flameshot already has a working X11 legacy fallback, a clearer fallback path or diagnostic would make this much easier for users on minimal X11 window managers such as dwm/i3/xmonad.

Thanks for your work on Flameshot.

[Kryszak]

I have the same issue on i3 session. I can confirm that setting the following fixes issue:

useX11LegacyScreenshot=true

[christosvlamis1]

I can reproduce the same issue on Arch Linux with i3/X11.

Flameshot 14.0.0-1 fails with the default config.
Downgrading to 13.3.0-2 works.
Keeping 14.0.0-1 and adding this fixes it:

[General]
useX11LegacyScreenshot=true

Environment:

• Arch Linux
• Window manager: i3
• XDG_CURRENT_DESKTOP=i3
• xdg-desktop-portal 1.22.0-1
• xdg-desktop-portal-gtk 1.15.3-1

So this appears to affect minimal X11 window managers beyond dwm, including i3.

[Aster89]

I can reproduce this on ArchLinux with XMonad.

Where do I apply the workaround? I mean, where's the file where I'd add the lines

[General]
useX11LegacyScreenshot=true

?

[ruhagen]

I can reproduce this on ArchLinux with XMonad.

Where do I apply the workaround? I mean, where's the file where I'd add the lines

[General]
useX11LegacyScreenshot=true

?

Try running:

flameshot config

Then open the General settings and look for the Use legacy X11 screenshot method option.

[Aster89]

Oh, yes, by going through the GUI settings I had found it, then I thought of looking under ~/.config/ for a flameshot dir, and there is indeed. Thanks @ruhagen nonetheless :)

[GasparVardanyan]

I have the same issue on i3 session. I can confirm that setting the following fixes issue:

useX11LegacyScreenshot=true

I have this problem too. This workaround helps, but with flameshot gui in dwm I get a floating window which gets out of screen by the size of statusbar height:

[ruhagen]

I have the same issue on i3 session. I can confirm that setting the following fixes issue:

useX11LegacyScreenshot=true

I have this problem too. This workaround helps, but with flameshot gui in dwm I get a floating window which gets out of screen by the size of statusbar height:

I had the same issue on dwm.

In my case, I fixed it by forcing the flameshot gui window to open as a floating window. After that, Flameshot stopped behaving like a tiled/fullscreen window and the screenshot overlay started working correctly again.

[GasparVardanyan]

In my case, I fixed it by forcing the flameshot gui window to open as a floating window. After that, Flameshot stopped behaving like a tiled/fullscreen window and the screenshot overlay started working correctly again.

By a window rule?

[GasparVardanyan]

BTW what is this new portal "dependency"? I don't have any portals:

And didn't had any problems until this one.

[ruhagen]

In my case, I fixed it by forcing the flameshot gui window to open as a floating window. After that, Flameshot stopped behaving like a tiled/fullscreen window and the screenshot overlay started working correctly again.

By a window rule?

Something like this in ~/.config/i3/config:

for_window [class="flameshot"] floating enable

reload i3 config:

i3-msg reload
i3-msg restart

If the rule does not work, you can check the actual window class with:

xprop | grep WM_CLASS

Then click the Flameshot window/overlay and adjust the class value in the i3 rule if needed.

[GasparVardanyan]

Ok, thanks a lot

[elfiyka]

I have successfully reproduced this issue on bspwm as well. I can confirm that adding useX11LegacyScreenshot=true to the config fixes the issue. Thank you, @ruhagen!

☁  ~  echo $DBUS_SESSION_BUS_ADDRESS
unix:path=/tmp/dbus-ukH7uPTfig,guid=4514055e8402b6d0df9e4b5c6a345527
☁  ~  echo $XDG_CURRENT_DESKTOP
bspwm
☁  ~  pacman -Q xdg-desktop-portal xdg-desktop-portal-gtk
xdg-desktop-portal 1.22.1-1
xdg-desktop-portal-gtk 1.15.3-1
☁  ~