Symfony: trouble adding Prototype to view.yml

I added the following to my view.yml

javascripts:    [%SF_PROTOTYPE_WEB_DIR%/js/prototype]

However, Symfony 开发者_运维知识库isn't including prototype properly. When I look at the source code, I see this:

<script type="text/javascript" src="/js/%SF_PROTOTYPE_WEB_DIR%/js/prototype.js"></script>

which I don't think is right. What am I doing wrong?

If you have prototype.js in your /web/js folder, all you need is

javascripts:  [prototype]

Symfony cannot replace sf_prototype_web_dir, because you do not have a config setting named like that.