From ff93928902970eb02bff46da93578ee838ce9720 Mon Sep 17 00:00:00 2001
From: Erich Gubler <erichdongubler@gmail.com>
Date: Wed, 26 Apr 2023 16:19:22 -0400
Subject: [PATCH] refactor(core)!: fold `Error` source chain `Display` output
 into shader errors

---
 wgpu-core/src/pipeline.rs | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/wgpu-core/src/pipeline.rs b/wgpu-core/src/pipeline.rs
index b58d5a427f0..9a7602a7dcc 100644
--- a/wgpu-core/src/pipeline.rs
+++ b/wgpu-core/src/pipeline.rs
@@ -7,7 +7,13 @@ use crate::{
     validation, Label, LifeGuard, Stored,
 };
 use arrayvec::ArrayVec;
-use std::{borrow::Cow, error::Error, fmt, marker::PhantomData, num::NonZeroU32};
+use std::{
+    borrow::Cow,
+    error::Error,
+    fmt::{self, Write},
+    marker::PhantomData,
+    num::NonZeroU32,
+};
 use thiserror::Error;
 
 /// Information about buffer bindings, which
@@ -92,7 +98,22 @@ impl fmt::Display for ShaderError<naga::WithSpan<naga::valid::ValidationError>>
         let config = term::Config::default();
         let mut writer = term::termcolor::NoColor::new(Vec::new());
 
-        let diagnostic = Diagnostic::error().with_labels(
+        let err_chain = {
+            let mut msg_buf = String::new();
+            write!(msg_buf, "{}", self.inner).unwrap();
+
+            let mut source = self.inner.source();
+            while let Some(next) = source {
+                // NOTE: The spacing here matters for presentation as a `Diagnostic`. Formula used:
+                //
+                // * 7 spaces to offset `error: `
+                // * 2 more spaces for "compact" indentation of the original error
+                writeln!(msg_buf, "         {next}").unwrap();
+                source = next.source();
+            }
+            msg_buf
+        };
+        let diagnostic = Diagnostic::error().with_message(err_chain).with_labels(
             self.inner
                 .spans()
                 .map(|&(span, ref desc)| {