After extracting the tar file, here's what I've found. Components of this source code include missing toolchains which are referenced at hard coded paths (an example being the build.sh file in the repo directory), unavailable kernel sources, and seemingly no unified build system that I could find. The source code may depend on proprietary resources which aren't included in the code. These components seem to be part of a WebOS browser system based on Chromium 87. You could potentially build some individual components, but this may require obtaining specific toolchains and modifying paths in the build instructions to match your system configuration. Perhaps building each component in isolation may work with specific components and enough effort.