From fbaf37a5f67397dfd389a26dd3c6cef45e0388ed Mon Sep 17 00:00:00 2001
From: Luca Forstner <luca.forstner@sentry.io>
Date: Sat, 7 Jan 2023 16:21:56 +0000
Subject: [PATCH] fix(nextjs): Don't write to `res.end` to fix `next export`

---
 packages/nextjs/src/config/wrappers/utils/responseEnd.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/nextjs/src/config/wrappers/utils/responseEnd.ts b/packages/nextjs/src/config/wrappers/utils/responseEnd.ts
index 21d5f5d850a5..82b6fb69ea28 100644
--- a/packages/nextjs/src/config/wrappers/utils/responseEnd.ts
+++ b/packages/nextjs/src/config/wrappers/utils/responseEnd.ts
@@ -31,7 +31,8 @@ export function autoEndTransactionOnResponseEnd(transaction: Transaction, res: S
   };
 
   // Prevent double-wrapping
-  if (!(res.end as WrappedResponseEndMethod).__sentry_original__) {
+  // res.end may be undefined during build when using `next export` to statically export a Next.js app
+  if (res.end && !(res.end as WrappedResponseEndMethod).__sentry_original__) {
     fill(res, 'end', wrapEndMethod);
   }
 }