From 85abbfa214c777aac1e0685097b57a2b324746f5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bastian=20M=C3=BCller?= <bastian@turbolent.com>
Date: Thu, 25 Jul 2024 14:44:04 -0700
Subject: [PATCH 1/2] Revert "Remove stacktrace from errors"

---
 runtime/errors/errors.go | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/runtime/errors/errors.go b/runtime/errors/errors.go
index 949f4896d9..a6bbd39fa1 100644
--- a/runtime/errors/errors.go
+++ b/runtime/errors/errors.go
@@ -20,6 +20,7 @@ package errors
 
 import (
 	"fmt"
+	"runtime/debug"
 
 	"golang.org/x/xerrors"
 )
@@ -141,7 +142,8 @@ func (e MemoryError) Error() string {
 //
 // NOTE: This error is not used for errors occur due to bugs in a user-provided program.
 type UnexpectedError struct {
-	Err error
+	Err   error
+	Stack []byte
 }
 
 var _ InternalError = UnexpectedError{}
@@ -150,13 +152,15 @@ func (UnexpectedError) IsInternalError() {}
 
 func NewUnexpectedError(message string, arg ...any) UnexpectedError {
 	return UnexpectedError{
-		Err: fmt.Errorf(message, arg...),
+		Err:   fmt.Errorf(message, arg...),
+		Stack: debug.Stack(),
 	}
 }
 
 func NewUnexpectedErrorFromCause(err error) UnexpectedError {
 	return UnexpectedError{
-		Err: err,
+		Err:   err,
+		Stack: debug.Stack(),
 	}
 }
 
@@ -165,7 +169,7 @@ func (e UnexpectedError) Unwrap() error {
 }
 
 func (e UnexpectedError) Error() string {
-	return fmt.Sprintf("internal error: %s", e.Err.Error())
+	return fmt.Sprintf("internal error: %s\n%s", e.Err.Error(), e.Stack)
 }
 
 // DefaultUserError is the default implementation of UserError interface.

From 158c82fb57ef1d17690782b1bcb040eaaa66eafb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bastian=20M=C3=BCller?= <bastian@turbolent.com>
Date: Thu, 25 Jul 2024 14:50:47 -0700
Subject: [PATCH 2/2] put stack traces behind feature flag

---
 runtime/errors/errors.go | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/runtime/errors/errors.go b/runtime/errors/errors.go
index a6bbd39fa1..d465852747 100644
--- a/runtime/errors/errors.go
+++ b/runtime/errors/errors.go
@@ -146,21 +146,24 @@ type UnexpectedError struct {
 	Stack []byte
 }
 
+var StackTracesEnabled = true
+
 var _ InternalError = UnexpectedError{}
 
 func (UnexpectedError) IsInternalError() {}
 
 func NewUnexpectedError(message string, arg ...any) UnexpectedError {
-	return UnexpectedError{
-		Err:   fmt.Errorf(message, arg...),
-		Stack: debug.Stack(),
-	}
+	return NewUnexpectedErrorFromCause(fmt.Errorf(message, arg...))
 }
 
 func NewUnexpectedErrorFromCause(err error) UnexpectedError {
+	var stack []byte
+	if StackTracesEnabled {
+		stack = debug.Stack()
+	}
 	return UnexpectedError{
 		Err:   err,
-		Stack: debug.Stack(),
+		Stack: stack,
 	}
 }
 
@@ -169,7 +172,12 @@ func (e UnexpectedError) Unwrap() error {
 }
 
 func (e UnexpectedError) Error() string {
-	return fmt.Sprintf("internal error: %s\n%s", e.Err.Error(), e.Stack)
+	message := e.Err.Error()
+	if len(e.Stack) == 0 {
+		return fmt.Sprintf("unexpected error: %s", message)
+	} else {
+		return fmt.Sprintf("unexpected error: %s\n%s", message, e.Stack)
+	}
 }
 
 // DefaultUserError is the default implementation of UserError interface.