fix(linux): start on Wayland with the NVIDIA driver (#1625)

WebKitGTK's DMA-BUF renderer fails on a Wayland session with the NVIDIA driver ("Error 71 (Protocol error) dispatching to Wayland display") and the app exits before showing a window. On that combination WEBKIT_DISABLE_DMABUF_RENDERER=1 is set at startup unless the user already set it.

src-tauri/src/lib.rs

@@ -10,6 +10,8 @@ mod dev;
 mod events;
 mod jump_list;
 #[cfg(any(target_os = "linux", test))]
+mod linux_webkit;
+#[cfg(any(target_os = "linux", test))]
 mod linux_window_state;
 mod logging;
 #[cfg(target_os = "macos")]
@@ -68,6 +70,8 @@ pub fn run() {
     // Before the first window: one taskbar identity for every launch path.
     jump_list::set_app_id(&context.config().identifier);
     logging::init(&context.config().identifier);
+    #[cfg(target_os = "linux")]
+    linux_webkit::configure();
 
     let refresh_shell_path = ide_host::shell_env::inherit_login_shell_path(&context.config().identifier);
     // Managed LSP/DAP installs; must run before other threads start and before PATH is cached.

src-tauri/src/linux_webkit.rs

@@ -0,0 +1,51 @@
+//! WebKitGTK's DMA-BUF renderer fails on Wayland with the NVIDIA driver: the window
+//! never shows and GDK logs "Error 71 (Protocol error) dispatching to Wayland display".
+//! On that combination the renderer is turned off before the first web view is created.
+
+const DISABLE_DMABUF: &str = "WEBKIT_DISABLE_DMABUF_RENDERER";
+
+/// Run before other threads start (`set_var`).
+#[cfg(target_os = "linux")]
+pub fn configure() {
+    let nvidia = ["/proc/driver/nvidia/version", "/sys/module/nvidia"].iter().any(|p| std::path::Path::new(p).exists());
+    if disable_dmabuf(|k| std::env::var(k).ok(), nvidia) {
+        tracing::info!("Wayland with the NVIDIA driver: {DISABLE_DMABUF}=1");
+        unsafe { std::env::set_var(DISABLE_DMABUF, "1") };
+    }
+}
+
+/// A Wayland session on the NVIDIA driver, unless the user already set the variable.
+fn disable_dmabuf(var: impl Fn(&str) -> Option<String>, nvidia: bool) -> bool {
+    if !nvidia || var(DISABLE_DMABUF).is_some() {
+        return false;
+    }
+    let wayland_display = var("WAYLAND_DISPLAY").is_some_and(|v| !v.is_empty());
+    // GDK tries the backends of `GDK_BACKEND` in order.
+    let gdk_wayland =
+        var("GDK_BACKEND").is_none_or(|b| matches!(b.split(',').next().map(str::trim), Some("wayland" | "*" | "")));
+    wayland_display && gdk_wayland
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn decide(vars: &[(&str, &str)], nvidia: bool) -> bool {
+        disable_dmabuf(|k| vars.iter().find(|(name, _)| *name == k).map(|(_, v)| v.to_string()), nvidia)
+    }
+
+    #[test]
+    fn turns_the_dmabuf_renderer_off_on_wayland_with_nvidia_only() {
+        assert!(decide(&[("WAYLAND_DISPLAY", "wayland-0")], true));
+        assert!(decide(&[("WAYLAND_DISPLAY", "wayland-0"), ("GDK_BACKEND", "wayland,x11")], true));
+        assert!(!decide(&[("WAYLAND_DISPLAY", "wayland-0")], false));
+        assert!(!decide(&[("DISPLAY", ":0")], true));
+        assert!(!decide(&[("WAYLAND_DISPLAY", "")], true));
+        assert!(!decide(&[("WAYLAND_DISPLAY", "wayland-0"), ("GDK_BACKEND", "x11")], true));
+    }
+
+    #[test]
+    fn keeps_the_users_own_setting() {
+        assert!(!decide(&[("WAYLAND_DISPLAY", "wayland-0"), (DISABLE_DMABUF, "0")], true));
+    }
+}