As a first step, you'll have to create and enter a folder with the appropriate name. To do that, run these commands:
mkdir spark
cd spark
repo init -u https://github.com/Spark-Rom/manifest -b pyro
repo sync --force-sync --optimized-fetch --no-tags --no-clone-bundle --prune -j$(nproc --all)
In case you are building Mac OS X, you are required to install coreutils from MacPorts before you continue. In order to build, use this command:
. build/env*
lunch spark_<devicecodename>-userdebug
mka bacon -j$(nproc --all)
Be sure to check our documents repo for any queries.