fix CI

japaric · japaric · commit 9c2ec7b18560 · 2017-12-09T12:50:04.000+01:00
diff --git a/ci/script.sh b/ci/script.sh
@@ -16,7 +16,7 @@ test_svd() {
 main() {
     cross check --target $TARGET
 
-    if [ -z $VENDOR ]; then
+    if [ -z ${VENDOR-} ]; then
         return
     fi
 
