From 7b90474b7066c74d33025d80def7c458bc420fc0 Mon Sep 17 00:00:00 2001
From: Tobias Kaupat <tobias.kaupat@lobaro.de>
Date: Wed, 21 Oct 2026 00:31:12 +0200
Subject: [PATCH] docs: note BuildKit requirement in README

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
---
 README.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/README.md b/README.md
index f985d46..35f8de0 100644
--- a/README.md
+++ b/README.md
@@ -92,6 +92,8 @@ Build the container (the container is named `backup-test`):
 ./build.sh
 ```
 
+The image needs BuildKit (default since Docker 23; on older Docker set `DOCKER_BUILDKIT=1`).
+
 Run the container:
 ```
 ./run.sh