Restrict it to arch where there is a package

core/base/Dockerfile

@@ -13,7 +13,12 @@ RUN set -euxo pipefail \
   ; addgroup -Sg ${MAILU_GID} mailu \
   ; adduser -Sg ${MAILU_UID} -G mailu -h /app -g "mailu app" -s /bin/bash mailu \
   ; apk add --no-cache bash ca-certificates curl python3 tzdata \
-  ; apk add --repository=http://dl-cdn.alpinelinux.org/alpine/edge/testing hardened-malloc
+  ; machine="$(uname -m)" \
+  ; ( [[ "${machine}" == x86_64 ]] || \
+      [[ "${machine}" == armv8* ]] || \
+      [[ "${machine}" == aarch64 ]] ) && \
+    echo "Installing hardened-malloc" && \
+    apk add --repository=http://dl-cdn.alpinelinux.org/alpine/edge/testing hardened-malloc
 
 WORKDIR /app