Screenshot does not contains the `bevy_egui` GUI in 0.15 anymore

[thmxv]

Bevy version

0.15

What you did

I ported my application to Bevy 0.15. Now the screenshot does not contains the bevy_egui GUI anymore. It did in Bevy 0.14.

What went wrong

I was expecting the screenshot to capture everything in the primary window like it was in 0.14.

Additional information

I tried to change the system order to make sure the command to spawn the Screenshot component was done after drawing the GUI and after some bevy_egui internal systems, and every order I thought could fix the issue but without any luck.

I also opened a bevy_egui issue thinking this might be a issue related to this plugin: vladbat00/bevy_egui#329

I do not know what to try or what to look for in order to try new workaround. Any suggestion is welcome.

[thmxv]

Here are some screenshots generated.
Bevy 0.14:

Bevy 0.15:

[alice-i-cecile]

#14833 is the most likely candidate.

[vladbat00]

Is there anything I can do on the bevy_egui end to adapt to the changes? I've looked through the screenshots related code, but I haven't found any obvious changes that could lead to this.
My first thought was "maybe we can just add an edge to a node that renders screenshots", but there isn't really a node, submitting screenshot commands is supposed to happen in the end of the whole render graph if I'm reading the code correctly:

    let res = RenderGraphRunner::run(
        graph,
        render_device.clone(), // TODO: is this clone really necessary?
        diagnostics_recorder,
        &render_queue.0,
        &render_adapter.0,
        world,
        |encoder| {
            crate::view::screenshot::submit_screenshot_commands(world, encoder);
            crate::gpu_readback::submit_readback_commands(world, encoder);
        },
    );

the last lambda is passed as the finalizer: impl FnOnce(&mut wgpu::CommandEncoder) argument, which supposedly means that it's expected to submit its render commands last?..

Or maybe bevy_egui just shouldn't render to a window's swapchain texture directly? I noticed this comment for ExtractedWindow::swap_chain_texture_view, I'm not sure if this has any implications for the way we render, and I couldn't find where the it changes to point to an alternative texture for taking screenshots.

    /// Note: this will not always be the swap chain texture view. When taking a screenshot,
    /// this will point to an alternative texture instead to allow for copying the render result
    /// to CPU memory.
    pub swap_chain_texture_view: Option<TextureView>,

Or this is something that needs to be fixed just on the Bevy's end...
I don't have a good grasp on rendering so these are just my random thoughts and observations.

Anyone's help with an understanding of render systems would be really welcome! Thank you.

[alice-i-cecile]

Or maybe bevy_egui just shouldn't render to a window's swapchain texture directly?

This is my expectation, but I'm far from a rendering expert. It feels like you're stepping outside of Bevy's preferred rendering model by doing that.