Changes

The config.sh step can take quite a while, because it downloads a large amount of data. Once that finishes, you need to apply a patch to the gecko checkout (for now; the patches are making their way through reviews etc.). Download the patch here https://pastebin.mozilla.org/6790989 and then apply to your <code>B2G/gecko</code> subdirectory by running the command  (cd gecko && git apply [the patch you downloaded]) Next, either copy the files <code>device/rpi/rpi/custom-settings.json</code> and <code>device/rpi/rpi/custom-prefs.js</code> in your <code>gaia/build/config/</code> directory, or --- if you already have custom settings or prefs --- append the contents of those files to your existing custom-* files. Finally, build b2g