a-b-street/abstreet · critical

Your videocard doesn't support the OpenGL mode requested…

Error message

Your videocard doesn't support the OpenGL mode requested. This is a common issue when running inside a virtual machine; please run natively if possible. See https://github.com/a-b-street/abstreet/issues/103 for more info, and feel free to ask for help using that issue.\n\nError: {:?}

What it means

widgetry's glutin/glow backend tries to build an OpenGL windowed context, falling back to a vsync-enabled context if the default fails. If both fail, it panics: the GPU/driver cannot provide the requested OpenGL (3.x/GLSL 300 es) context — common in VMs or with missing/mesa-only drivers.

Solutions

1. Run natively (not in a VM) or enable 3D GPU acceleration/passthrough for the VM
2. Update the GPU driver, or install Mesa with software rendering (LIBGL_ALWAYS_SOFTWARE=1) as a fallback
3. Ensure a display/GLX/EGL context is available (run under X, not bare SSH/headless)
4. Check issue #103 (linked in the message) for known workarounds and ask there

Example fix

// run with software rendering as a workaround
LIBGL_ALWAYS_SOFTWARE=1 cargo run --bin game

// before launching the app, probe GL support
eprintln!("GL_VENDOR={:?} GL_RENDERER={:?}", std::env::var("GALLIUM_DRIVER"), std::env::var("LIBGL_ALWAYS_SOFTWARE"));

// detect context creation failure early
let ctx = glutin::ContextBuilder::new().build_windowed(window.clone(), &event_loop);
if ctx.is_err() {
    eprintln!("GPU context unavailable; try LIBGL_ALWAYS_SOFTWARE=1 or run natively");
}

When it happens

Trigger: Launching any widgetry app on a machine whose videocard/driver can't create the requested OpenGL context — default and vsync ContextBuilder both fail in build_windowed.

Common situations: Running inside a VM without GPU passthrough; headless CI machines; outdated or software-only graphics drivers; missing X display / Wayland quirks; old GPUs.

Related errors

• error compiling shader
• {}
• error building program
• error creating texture

AI-assisted analysis of a-b-street/abstreet@0964f29315 (2026-09-13). Data as JSON: /api/errors/11507be5099e2356. Report an issue: GitHub.

Appendix: source

Thrown at widgetry/src/backend_glow_native.rs:28

    // backend_glium.rs from git and bring the fallback behavior here. (Ideally, there'd be
    // something in glutin to directly express this.)
    let context = glutin::ContextBuilder::new()
        // 2 looks really bad, 4 looks alright. For thin lines at low zoom, 8 looks better, and
        // should have common videocard support.
        .with_multisampling(8)
        .with_depth_buffer(2)
        .build_windowed(window.clone(), &event_loop)
        .or_else(|err| {
            warn!("Trying default graphics context after standard graphics context failed with error: {:?}",  err);
            glutin::ContextBuilder::new().build_windowed(window.clone(), &event_loop)
        })
        .or_else(|err| {
            warn!("Trying graphics context with vsync after default graphics context failed with error: {:?}", err);
            glutin::ContextBuilder::new()
                .with_vsync(true)
                .build_windowed(window.clone(), &event_loop)
        }).unwrap_or_else(|err| {
        panic!("Your videocard doesn't support the OpenGL mode requested. This is a common issue when running inside a virtual machine; please run natively if possible. See https://github.com/a-b-street/abstreet/issues/103 for more info, and feel free to ask for help using that issue.\n\nError: {:?}", err);
    });

    let windowed_context = unsafe { context.make_current().unwrap() };
    let gl = unsafe {
        glow::Context::from_loader_function(|s| windowed_context.get_proc_address(s) as *const _)
    };

    let program = unsafe {
        build_program(
            &gl,
            include_str!("../shaders/vertex_140.glsl"),
            include_str!("../shaders/fragment_140.glsl"),
        )
        .or_else(|err| {
            warn!(
                "unable to build program with default shaderrs, falling back to v300. error: {:?}",
                err
            );

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