From 6124f8e8eb30ee16667a3f3297bb69cf92aee528 Mon Sep 17 00:00:00 2001
From: Jim Blandy <jimb@red-bean.com>
Date: Fri, 2 Dec 2022 14:03:15 -0800
Subject: [PATCH] wgpu-hal: Give a more helpful error when no backends are
 enabled.

---
 wgpu-hal/src/lib.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/wgpu-hal/src/lib.rs b/wgpu-hal/src/lib.rs
index b688e326d69..dcce62899d5 100644
--- a/wgpu-hal/src/lib.rs
+++ b/wgpu-hal/src/lib.rs
@@ -49,6 +49,15 @@
     clippy::pattern_type_mismatch,
 )]
 
+#[cfg(not(any(
+    feature = "dx11",
+    feature = "dx12",
+    feature = "gles",
+    feature = "metal",
+    feature = "vulkan"
+)))]
+compile_error!("No back ends enabled in `wgpu-hal`. Enable at least one backend feature.");
+
 #[cfg(all(feature = "metal", not(any(target_os = "macos", target_os = "ios"))))]
 compile_error!("Metal API enabled on non-Apple OS. If your project is not using resolver=\"2\" in Cargo.toml, it should.");
 #[cfg(all(feature = "dx12", not(windows)))]