hello_compute: check for missing command-line args

CHANGELOG.md

@@ -216,6 +216,7 @@ Passing an owned value `window` to `Surface` will return a `Surface<'static>`. S
 ### Examples
 
 - remove winit dependency from hello-compute example by @psvri in [#4699](https://github.com/gfx-rs/wgpu/pull/4699)
+- hello-compute example fix failure with "wgpu error: Validation Error" if arguments are missing by @vilcans in [#4939](https://github.com/gfx-rs/wgpu/pull/4939)
 
 ## v0.18.1 (2023-11-15)
 

examples/src/hello_compute/mod.rs

@@ -6,7 +6,7 @@ const OVERFLOW: u32 = 0xffffffff;
 
 #[cfg_attr(test, allow(dead_code))]
 async fn run() {
-    let numbers = if std::env::args().len() <= 1 {
+    let numbers = if std::env::args().len() <= 2 {
         let default = vec![1, 2, 3, 4];
         println!("No numbers were provided, defaulting to {default:?}");
         default