workaround build failure on AWS M6g instances

export-image/prerun.sh

@@ -39,8 +39,19 @@ BOOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^1:' | cut -d':' -f 4 | tr -d B)
 ROOT_OFFSET=$(echo "$PARTED_OUT" | grep -e '^2:' | cut -d':' -f 2 | tr -d B)
 ROOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^2:' | cut -d':' -f 4 | tr -d B)
 
-BOOT_DEV=$(losetup --show -f -o "${BOOT_OFFSET}" --sizelimit "${BOOT_LENGTH}" "${IMG_FILE}")
-ROOT_DEV=$(losetup --show -f -o "${ROOT_OFFSET}" --sizelimit "${ROOT_LENGTH}" "${IMG_FILE}")
+
+echo "Mounting BOOT_DEV..."
+until BOOT_DEV=$(losetup --show -f -o "${BOOT_OFFSET}" --sizelimit "${BOOT_LENGTH}" "${IMG_FILE}"); do
+	echo "Error in losetup for BOOT_DEV.  Retrying..."
+	sleep 5
+done
+
+echo "Mounting ROOT_DEV..."
+until ROOT_DEV=$(losetup --show -f -o "${ROOT_OFFSET}" --sizelimit "${ROOT_LENGTH}" "${IMG_FILE}"); do
+	echo "Error in losetup for ROOT_DEV.  Retrying..."
+	sleep 5
+done
+
 echo "/boot: offset $BOOT_OFFSET, length $BOOT_LENGTH"
 echo "/:     offset $ROOT_OFFSET, length $ROOT_LENGTH"