"wait -n" needs bash
-#! /bin/sh
+#! /bin/bash
set -ue
-if [ "${USE_FASTBOOT:-0}" = 1 ]; then
+if [[ "${USE_FASTBOOT:-0}" = 1 ]]; then
export USE_FASTBOOT=1
node --optimize_for_size --max_old_space_size=200 fastboot.js &
bin/start-nginx ./target/release/server &
