From 08bb0f985ab80512adaea5e79eb3b452763b1122 Mon Sep 17 00:00:00 2001
From: Lukasz Raczylo <lukasz@raczylo.com>
Date: Sat, 29 Aug 2026 13:54:07 +0100
Subject: [PATCH] fix(docker): declare ARG TARGETARCH so buildx cross-builds
 work

TARGETARCH was referenced but never declared, so every platform in a
multi-arch buildx run received an amd64 binary. The arm64 image
crashed on Raspberry Pi nodes with an exec format error.
---
 Dockerfile | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Dockerfile b/Dockerfile
index 93a202b..92bd8e4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,10 @@
 # Build stage
 FROM golang:1.26-alpine AS builder
 
+# Populated by buildx per platform; without this declaration the
+# GOARCH=${TARGETARCH:-amd64} below silently builds amd64 for every platform.
+ARG TARGETARCH
+
 # Install ca-certificates for HTTPS support
 RUN apk add --no-cache ca-certificates