All of Cobalt's dependencies (both compile and run-time) are installed in the sysroot directory using the setup.sh script. To avoid having to compile the dependencies every time, a packaged binary version of sysroot is stored on Google storage. cobaltb.py setup will download the pre-built sysroot from Google storage.
To upload a new version of sysroot on Google storage do the following:
rm -fr sysroot./setup.sh -u