> Juggler - Firefox Automation Protocol for implementing the Puppeteer API.
## Protocol
See [`//src/Protocol.js`](https://github.com/GoogleChrome/puppeteer/blob/master/experimental/juggler/src/Protocol.js).
## Building FF with Juggler
1. Clone Juggler repository
```bash
git clone https://github.com/aslushnikov/juggler
cd juggler
```
2. Checkout [pinned Firefox revision](https://github.com/aslushnikov/juggler/blob/master/FIREFOX_SHA) from mozilla [github mirror](https://github.com/mozilla/gecko-dev) into `//firefox` folder.
As of Jan. 2019 there is a known [bug](https://bugzilla.mozilla.org/show_bug.cgi?id=1493330) that will cause an entirely black screen when running the nightly build of firefox built with the **MacOSX SDK version 10.14.**
The easiest fix right now is downgrading your MacOSX SDK.
To do so:
1) Go to [this repo](https://github.com/phracker/MacOSX-SDKs) and install any **SDK version < 10.14** (e.g. 10.13 works fine)