From b20c45df10137927a031de4e27a0228e945c09f3 Mon Sep 17 00:00:00 2001
From: Brett McBride <brett.a.mcbride@gmail.com>
Date: Tue, 6 Feb 2024 12:32:25 +1100
Subject: [PATCH] log previous exception message from error writer (#1231)

it's not always clear from an exception message what the underlying issue was, so
also print out the previous exception's message, if available.
---
 src/API/Behavior/Internal/LogWriter/Formatter.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/API/Behavior/Internal/LogWriter/Formatter.php b/src/API/Behavior/Internal/LogWriter/Formatter.php
index 4cfd6f9d4..2677662b9 100644
--- a/src/API/Behavior/Internal/LogWriter/Formatter.php
+++ b/src/API/Behavior/Internal/LogWriter/Formatter.php
@@ -12,11 +12,13 @@ public static function format($level, string $message, array $context): string
             ? $context['exception']
             : null;
         if ($exception) {
+            $previous = $exception->getPrevious() ? $exception->getPrevious()->getMessage() : '';
             $message = sprintf(
-                'OpenTelemetry: [%s] %s [exception] %s%s%s',
+                'OpenTelemetry: [%s] %s [exception] %s [previous] %s%s%s',
                 $level,
                 $message,
                 $exception->getMessage(),
+                $previous,
                 PHP_EOL,
                 $exception->getTraceAsString()
             );