middleman/middleman — Issue #285: "page" directive in config.rb for nonexistant file should be an error
Author: bhollis
Created: 2012-02-27 07:34:27+00:00
State: open

We should fail fast, with a nice error message, when somebody has said something like:

```
page "page-doesnt-exist.html", :directory_index => false
```

They're obviously trying to configure a page that doesn't exist (or trying to proxy but forgot the proxy argument). Right now we give some sort of obscure error from deep down in the code, and only once the builder gets around to that page in the sitemap.