Core on Centos7

[sergeyPortfolio]

Hello dear team, I am trying to use slint.
And I found problem when I am building app on centos7

there is code which I use

import { LineEdit, ListView, GroupBox, CheckBox, GridBox, ComboBox, HorizontalBox, ListView, StandardListView, Button, VerticalBox } from "std-widgets.slint";


export global functionalPartForFirstWindow {
    in-out property<int> increase_counter: 42;
    callback request-increase-value();
    callback request-open-window();
}

export global functionalPartForSecondWindow {
    in-out property<int> decrease_counter: 42;
    callback request-decrease-value();
    callback request-close-window();
}

export component FirstWindow {
    Rectangle{
        VerticalBox {
            Text {
                text: "Counter: \{functionalPartForFirstWindow.increase_counter}";
            }

            Button {
                text: "Increase value";
                clicked => {
                    functionalPartForFirstWindow.request-increase-value();
                }
            }

            Button {
                text: "Open Window";
                clicked => {
                    functionalPartForFirstWindow.request-open-window();
                }
            }
        }
    }
}

export component SecWindow {
    Rectangle{
        VerticalBox {
            Text {
                text: "Counter: \{functionalPartForSecondWindow.decrease_counter}";
            }
            Button {
                text: "Decrease value";
                clicked => {
                    functionalPartForSecondWindow.request-decrease-value();
                }
            }

            Button {
                text: "close window";
                clicked => {
                    functionalPartForSecondWindow.request-close-window();
                }
            }

        }
    }
}

export component AppWindow inherits Window {

    in property<bool> showSecWindow: false;

    VerticalLayout {
        if showSecWindow : SecWindow {}

        if ( !showSecWindow ) : FirstWindow {}
    }
}

here is output:

RUST_BACKTRACE=full ./build/bin/ui-gui
thread '<unnamed>' panicked at api/cpp/lib.rs:48:6:
called `Result::unwrap()` on an `Err` value: Other("Could not initialize backend.\nError from Winit backend: Error initializing winit event loop: the requested operation is not supported by Winit\nNo backends configured.")
stack backtrace:
   0:     0x7f08135afac6 - std::backtrace_rs::backtrace::libunwind::trace::hbee8a7973eeb6c93
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
   1:     0x7f08135afac6 - std::backtrace_rs::backtrace::trace_unsynchronized::hc8ac75eea3aa6899
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f08135afac6 - std::sys_common::backtrace::_print_fmt::hc7f3e3b5298b1083
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7f08135afac6 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hbb235daedd7c6190
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f08135de4a0 - core::fmt::rt::Argument::fmt::h76c38a80d925a410
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/fmt/rt.rs:142:9
   5:     0x7f08135de4a0 - core::fmt::write::h3ed6aeaa977c8e45
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/fmt/mod.rs:1120:17
   6:     0x7f08135abeff - std::io::Write::write_fmt::h78b18af5775fedb5
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/io/mod.rs:1810:15
   7:     0x7f08135af8a4 - std::sys_common::backtrace::_print::h5d645a07e0fcfdbb
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f08135af8a4 - std::sys_common::backtrace::print::h85035a511aafe7a8
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f08135b0fa7 - std::panicking::default_hook::{{closure}}::hcce8cea212785a25
  10:     0x7f08135b0d09 - std::panicking::default_hook::hf5fcb0f213fe709a
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/panicking.rs:292:9
  11:     0x7f08135b1438 - std::panicking::rust_panic_with_hook::h095fccf1dc9379ee
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/panicking.rs:779:13
  12:     0x7f08135b1312 - std::panicking::begin_panic_handler::{{closure}}::h032ba12139b353db
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/panicking.rs:657:13
  13:     0x7f08135affc6 - std::sys_common::backtrace::__rust_end_short_backtrace::h9259bc2ff8fd0f76
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/sys_common/backtrace.rs:171:18
  14:     0x7f08135b1070 - rust_begin_unwind
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/panicking.rs:645:5
  15:     0x7f0811d18a15 - core::panicking::panic_fmt::h784f20a50eaab275
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/panicking.rs:72:14
  16:     0x7f0811d19053 - core::result::unwrap_failed::h03d8a5018196e1cd
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/result.rs:1649:5
  17:     0x7f0812d4391b - core::result::Result<T,E>::unwrap::h5036be18ca21dad8
                               at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/result.rs:1073:23
  18:     0x7f0811d1a3ad - slint_ensure_backend
                               at /home/workspace/app/build/_deps/slint-src/api/cpp/lib.rs:44:5
Aborted (core dumped)

could you please advise how to resolve this problem.

[ogoffart]

The error is:

Could not initialize backend.
Error from Winit backend: Error initializing winit event loop: the requested operation is not supported by Winit

Which may be because winit can't access the X11 DISPLAY or the wayland file decriptor.
Are you using X11 or wayland?
Any other error in the console before?

(Note: I converted this to a discussion because this is most likeley not a bug in slint but a configuration problem)

[makingpippop]

I'm facing the same issue.

I'm running Slint in a Docker image using VSCode's DevContainers on Windows 10.
I've installed vcxsrv to act as my X11 server.
In my image I've installed, configure and validated my X11 client.

which xauth
/usr/bin/xauth

echo $DISPLAY
<my-ip>:0

xeyes

This opens and shows me the sample app (provided by x11-apps). However when running this sample project from Slint's website

_{--- main.rs}

slint::include_modules!();

fn main() -> Result<(), slint::PlatformError> {
    let main_window = MainWindow::new()?;

    main_window.run()
}

_{--- app-window.slint}

export component MainWindow inherits Window {
    Text {
        text: "hello world";
        color: green;
    }
}

I get :
Error: Other("Could not initialize backend.\nError from Winit backend: Error initializing winit event loop: os error at /usr/local/cargo/registry/src/index.crates.io-6f17d22bba15001f/winit-0.30.8/src/platform_impl/linux/mod.rs:787: Failed to load one of xlib's shared libraries\nNo backends configured.")

Thanks for your help!

[ogoffart]

Failed to load one of xlib's shared libraries

Looks like you are missing some dependency.
Make sure you have the XCB and XLib lib installed on your system.

[makingpippop]

Thank you! I should've read the error more carefully... Is there a place where the required libraries are listed? I'm pretty new to this concept and would like a better understand of what is required.

Based on this discussion I see these libraries : libx11-dev libxcursor-dev libx11-xcb-dev libxi-dev libxkbcommon-x11-dev, but I don't see how I could've known that.