diff --git a/script/run_local_ci.sh b/script/run_local_ci.sh
index 733b41d..fbfd4f4 100755
--- a/script/run_local_ci.sh
+++ b/script/run_local_ci.sh
@@ -233,6 +233,9 @@
 export -f run_one_test
 
 workspace="${workspace:?}"
+if [ "$retain_paths" -eq 0 ]; then
+	gcc_space="${gcc_space:?Environment variable 'gcc_space' must be set}"
+fi
 ci_root="$(readlink -f "$(dirname "$0")/..")"
 
 # If this script was invoked with bash -x, have subsequent build/run invocations