I use Mint 19 so a Ubuntu 18.04.x based build system so better upgrade your distribution to build this fork. Btw. you forked a fork? Better rebase against upstream and then add your changes / files. (GitHub - jaykass/LibreELEC.tv: 'Just enough OS' for Kodi)
Can you upload your terminal output when moonlight fails to build?
Should be stored in Configfiles/google-chrome