sys.warnoptions must be a list

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/SysModuleBuiltins.java

@@ -199,7 +199,11 @@ public void postInitialize(PythonCore core) {
         sys.setAttribute("dont_write_bytecode", context.getOption(PythonOptions.DontWriteBytecodeFlag));
         String pycachePrefix = context.getOption(PythonOptions.PyCachePrefix);
         sys.setAttribute("pycache_prefix", pycachePrefix.isEmpty() ? PNone.NONE : pycachePrefix);
-        sys.setAttribute("warnoptions", core.factory().createTuple(context.getOption(PythonOptions.WarnOptions).split(",")));
+
+        String[] strWarnoptions = context.getOption(PythonOptions.WarnOptions).split(",");
+        Object[] warnoptions = new Object[strWarnoptions.length];
+        System.arraycopy(strWarnoptions, 0, warnoptions, 0, strWarnoptions.length);
+        sys.setAttribute("warnoptions", core.factory().createList(warnoptions));
         sys.setAttribute("__flags__", core.factory().createTuple(new Object[]{
                         false, // bytes_warning
                         !context.getOption(PythonOptions.PythonOptimizeFlag), // debug