fix senamtics

Author: native-api

test/stubs/stub

@@ -28,9 +28,7 @@ acquire_lock() {
   local acquired=
   while (( SECONDS <= start + $acquire_timeout )); do
 
-    set -o noclobber
-    echo -n > "$STUB_LOCKFILE" 2>/dev/null && acquired=1
-    set +o noclobber
+    ( set -o noclobber; echo -n >"$STUB_LOCKFILE" ) 2>/dev/null && acquired=1
 
     if [[ -n $acquired ]]; then
       trap release_lock EXIT