To get started with the Cosmic-OS sources, you'll need to get familiar with Git and Repo.
Use corona-release branch for Android Pie and pulsar-release branch for Android Oreo.
repo init -u https://github.com/cos-temp/manifest.git -b q-staging
repo sync --no-tags --no-clone-bundle --force-sync -c
-j# -Set jobs by just replacing # with what you wish
This will initialize the new repository and begin the initial sync. This can take a while!
Initialize the ROM environment with the envsetup.sh script. By entering command (i).
. build/envsetup.sh
lunch cos_<device>-userdebug
brunch <device>