Error in browser: `process` is not defined

When calling `path.resolve("tmp", ".."), this branch is triggered, causing an error in the browser (line 124 in index.js):

```js
if (cwd === undefined)
cwd = process.cwd();
path = cwd;
```

```
Uncaught ReferenceError: process is not defined
```

I think this error should be caught.