title: Why wouldn't I use npm to install yarn?
body: <p>In <a href="https://code.facebook.com/posts/1840075619545360" rel="noreferrer">the blog post announcing yarn (an alternative npm client)</a> they say, "The easiest way to get started is to run <code>npm install -g yarn</code>". But if you go to <a href="https://yarnpkg.com/en/docs/install" rel="noreferrer">the "install yarn" page in their docs</a>, "npm install yarn" isn't listed on any of the platform-specific installation pages, and it's only offered as the third of three options on the "Alternatives" page. Furthermore when you <code>npm install</code> yarn it prints a deprecation warning, "It is recommended to install Yarn using the native installation method for your environment." So my question is if <code>npm install</code> is the easiest installation method, why isn't it a recommended method in their docs? Are there disadvantages to installing yarn using <code>npm</code>?</p>