only test examples which have a main.py

test_startup.sh

@@ -31,6 +31,8 @@ error=0
 check main.py || error=1
 for path in examples/*
 do
-    check $path/main.py || error=1
+    if test -f $path/main.py; then
+        check $path/main.py || error=1
+    fi
 done
 test $error -eq 0