Runtime error when initiating screencasting

[isti115]

The Settings part of the portal seems to be working perfectly, but when I try to initiate a ScreenCast, I get the following error:

2023-12-29T10:54:58.517785Z  INFO
  dispatch_message {
    msg=Msg {
      type: MethodCall,
      sender: UniqueName(Str(Borrowed(":1.15"))),
      path: ObjectPath("/org/freedesktop/portal/desktop"),
      iface: InterfaceName(Str(Borrowed("org.freedesktop.impl.portal.ScreenCast"))),
      member: MemberName(Str(Borrowed("CreateSession"))), body: Signature("oosa{sv}")
    }
  }:dispatch_method_call {
    msg=Msg {
      type: MethodCall,
      sender: UniqueName(Str(Borrowed(":1.15"))),
      path: ObjectPath("/org/freedesktop/portal/desktop"),
      iface: InterfaceName(Str(Borrowed("org.freedesktop.impl.portal.ScreenCast"))),
      member: MemberName(Str(Borrowed("CreateSession"))),
      body: Signature("oosa{sv}")
    }
  }:dispatch_method_call_try {
    msg=Msg {
      type: MethodCall,
      sender: UniqueName(Str(Borrowed(":1.15"))),
      path: ObjectPath("/org/freedesktop/portal/desktop"),
      iface: InterfaceName(Str(Borrowed("org.freedesktop.impl.portal.ScreenCast"))),
      member: MemberName(Str(Borrowed("CreateSession"))),
      body: Signature("oosa{sv}")
    }
  }:
  xdg_desktop_portal_luminous::screencast:
  Start shot:
    path :/org/freedesktop/portal/desktop/request/1_77/obs4,
    appid: thread 'tokio-runtime-worker' panicked at 'called `Result::unwrap()` on an `Err` value: Connect(NoWaylandLib)', src/screencast.rs:194:63

I am running the binary from the development shell provided through flake.nix, so I assume, that the Wayland library should be present, as it's among the nativeBuildInputs. Also, wayshot works without any issues.

[Decodetalkers]

line 194 is libwayshot init connection, and it says there is no waylandlib

[Decodetalkers]

so, I think that is there is no wayland_display for the service

[Decodetalkers]

you can try to start it from commandline not systemd service..

it should need a WAYLAND_DISPLAY

[isti115]

Thanks for helping me troubleshoot this!
The error message was in fact captured by running it in the terminal, but I also have my WAYLAND_DISPLAY imported into the systemd environment, so there has got to be another cause at play.

In case anyone is facing the same issue, the temporary workaround I came up with was using the wlr portal for screencasting and relying on the luminous portal for the accent-color and cholor-scheme settings only.
~/.config/xdg-desktop-portal/portals.conf:

[preferred]
default=wlr
org.freedesktop.impl.portal.Settings=luminous

[Shinyzenith]

Thanks for helping me troubleshoot this! The error message was in fact captured by running it in the terminal, but I also have my WAYLAND_DISPLAY imported into the systemd environment, so there has got to be another cause at play.

In case anyone is facing the same issue, the temporary workaround I came up with was using the wlr portal for screencasting and relying on the luminous portal for the accent-color and cholor-scheme settings only. ~/.config/xdg-desktop-portal/portals.conf:

[preferred]
default=wlr
org.freedesktop.impl.portal.Settings=luminous

This is really interesting. Just to be clear, I am a Nix newbie and I copied the flake.nix from another project...maybe my flake code is the real issue here?

Are you sure luminous portal is receiving the WAYLAND_DISPLAY properly? Because wayshot and luminous use the same code for the backend ( libwayshot ). If wayshot works, there's no reason why luminous shouldn't.

Can you provide your distribution and compositor?

[isti115]

Can you provide your distribution and compositor?

Of course, it's NixOS 23.11 and river 0.2.6, but I tried under Sway as well and got the same result. I'll make a build that prints the environmental variables just to be sure that WAYLAND_DISPLAY is present and correct for the portal, but I would be very surprised if it wasn't, since as I've said, I have tried it from a terminal and have imported (and verified via systemctl --user show-environment) it into the systemd environment as well.

[Shinyzenith]

Hm still sounds like it's worth a shot. Please let me know!