From 904f536b18ac0476c4ad045e6983209727d9fe6a Mon Sep 17 00:00:00 2001
From: Ryan Levick <ryan.levick@fermyon.com>
Date: Wed, 5 Apr 2023 18:07:58 +0200
Subject: [PATCH] Show error source list when printing handler error

Signed-off-by: Ryan Levick <ryan.levick@fermyon.com>
---
 sdk/rust/macro/src/lib.rs | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/sdk/rust/macro/src/lib.rs b/sdk/rust/macro/src/lib.rs
index e7c11cbde1..d28b4966be 100644
--- a/sdk/rust/macro/src/lib.rs
+++ b/sdk/rust/macro/src/lib.rs
@@ -22,9 +22,14 @@ pub fn http_component(_attr: TokenStream, item: TokenStream) -> TokenStream {
 
                 match #func_name(req.try_into().expect("cannot convert from Spin HTTP request")) {
                     Ok(resp) => resp.try_into().expect("cannot convert to Spin HTTP response"),
-                    Err(e) => {
-                        let body = e.to_string();
+                    Err(error) => {
+                        let body = error.to_string();
                         eprintln!("Handler returned an error: {}", body);
+                        let mut error: &(dyn std::error::Error + 'static) = &*error;
+                        while let Some(source) = error.source() {
+                            eprintln!("  caused by: {}", source);
+                            error = source;
+                        }
                         spin_http::Response {
                             status: 500,
                             headers: None,