Iced: `cargo run --example tour` not working on debian

[fabianboesiger]

I'm trying to compile the tour example of iced, but it gives me the following error:

failed to run custom build command for `servo-fontconfig-sys v4.0.8`

Caused by:
  process didn't exit successfully: `/home/fabian/git/iced/target/debug/build/servo-fontconfig-sys-d1a79e2a5442f475/build-script-build` (exit code: 101)
--- stdout
cd /home/fabian/git/iced/target/debug/build/servo-fontconfig-sys-897f4e149b715354/out && \
    CC="gcc" \
    AR="ar" \
    FREETYPE_CFLAGS="" \
    FREETYPE_LIBS="" \
    CFLAGS=""" -fPIC" \
    /home/fabian/.cargo/registry/src/github.com-1ecc6299db9ec823/servo-fontconfig-sys-4.0.8/configure \
    --disable-docs \
    --disable-shared \
     \
    --host=x86_64-unknown-linux-gnu --sysconfdir=/etc --localstatedir=/var &&

--- stderr
/bin/sh: 11: Syntax error: end of file unexpected
make: *** [makefile.cargo:83: /home/fabian/git/iced/target/debug/build/servo-fontconfig-sys-897f4e149b715354/out/Makefile] Fehler 2
thread 'main' panicked at 'assertion failed: Command::new("make").env("MAKEFLAGS",
                         env::var("CARGO_MAKEFLAGS").unwrap_or_default()).args(&["-R",
                                                                                 "-f",
                                                                                 "makefile.cargo"]).status().unwrap().success()', /home/fabian/.cargo/registry/src/github.com-1ecc6299db9ec823/servo-fontconfig-sys-4.0.8/build.rs:20:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.

warning: build failed, waiting for other jobs to finish...
error: build failed

It seems to have something to do with fontconfig somehow?

[hecrj]

I think this is related to #58. Do you have pkg-config installed?

[fabianboesiger]

Yes, pkg-config is installed.

pkg-config --version returns 0.29, but in here, I found the following code:

if let Ok(lib) = pkg_config::Config::new().atleast_version("2.11.1").find("fontconfig") {
        println!("cargo:incdir={}", lib.include_paths[0].clone().into_os_string().into_string().unwrap());
        return;
}

Is the atleast_version("2.11.1") related to this? I have no idea.

[fabianboesiger]

I have found a solution for the issue. The error is related to fontconfig, which is also used in Servo. Servo recommends the following command:

sudo apt install git curl autoconf libx11-dev \
    libfreetype6-dev libgl1-mesa-dri libglib2.0-dev xorg-dev \
    gperf g++ build-essential cmake virtualenv python-pip \
    libssl-dev libbz2-dev liblzma-dev libosmesa6-dev libxmu6 libxmu-dev \
    libglu1-mesa-dev libgles2-mesa-dev libegl1-mesa-dev libdbus-1-dev \
    libharfbuzz-dev ccache clang libunwind-dev \
    libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev libgstreamer-plugins-bad1.0-dev autoconf2.13 llvm-dev

After installing these libraries, the original error was resolved. However another error occured while compiling the tour example:

thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:378:21
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.37/src/backtrace/libunwind.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.37/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src/libstd/sys_common/backtrace.rs:76
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src/libstd/sys_common/backtrace.rs:60
   4: core::fmt::write
             at src/libcore/fmt/mod.rs:1030
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1412
   6: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:64
   7: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:49
   8: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:196
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:210
  10: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:473
  11: std::panicking::continue_panic_fmt
             at src/libstd/panicking.rs:380
  12: rust_begin_unwind
             at src/libstd/panicking.rs:307
  13: core::panicking::panic_fmt
             at src/libcore/panicking.rs:85
  14: core::panicking::panic
             at src/libcore/panicking.rs:49
  15: core::option::Option<T>::unwrap
             at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libcore/macros.rs:12
  16: wgpu_request_adapter
             at /home/fabian/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-native-0.4.1/src/instance.rs:474
  17: wgpu::Adapter::request
             at /home/fabian/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.4.0/src/lib.rs:545
  18: iced_wgpu::renderer::Renderer::new
             at wgpu/src/renderer.rs:51
  19: <iced_wgpu::renderer::Renderer as iced_native::renderer::windowed::Windowed>::new
             at wgpu/src/renderer.rs:418
  20: iced_winit::application::Application::run
             at ./winit/src/application.rs:129
  21: iced::application::Application::run
             at ./src/application.rs:140
  22: iced::sandbox::Sandbox::run
             at ./src/sandbox.rs:128
  23: tour::main
             at examples/tour.rs:10
  24: std::rt::lang_start::{{closure}}
             at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/rt.rs:64
  25: std::rt::lang_start_internal::{{closure}}
             at src/libstd/rt.rs:49
  26: std::panicking::try::do_call
             at src/libstd/panicking.rs:292
  27: __rust_maybe_catch_panic
             at src/libpanic_unwind/lib.rs:80
  28: std::panicking::try
             at src/libstd/panicking.rs:271
  29: std::panic::catch_unwind
             at src/libstd/panic.rs:394
  30: std::rt::lang_start_internal
             at src/libstd/rt.rs:48
  31: std::rt::lang_start
             at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/rt.rs:64
  32: main
  33: __libc_start_main
  34: _start
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[hecrj]

@fabianboesiger You should not need to build fontconfig from source in most environments. Is your fontconfig at least 2.11.1?

About the issue, this is most likely related to wgpu. Try any of the examples in the wgpu repository and see if the same issue happens there. Some people have fixed the issue by updating their graphics drivers.

[fabianboesiger]

fontconfig is version 2.13.1.

You are probably right about the relation with wgpu, because if I try running the examples they always panic with internal error: entered unreachable code. The graphics driver (Intel HD Graphics) is up to date.

[manokara]

Given the panic at the request_adapter function, which only happens if no supported devices are found, you either don't have the Vulkan drivers installed or your Intel HD Graphics doesn't support Vulkan.

[fabianboesiger]

Thank you so much for your help! Both the wgpu and the iced examples are now working after installing the mesa-vulkan-drivers package.

Maybe add a list of the required packages somewhere in the README.md?

[David-OConnor]

Running into this as well; have no code other than iced = "0.1.0-beta", in Cargo.toml. How do you install pkg-config?

[fabianboesiger]

With apt, you can simply apt update && apt install pkg-config.

[David-OConnor]

Thank you