It looks like some builds are breaking because:
Firebase CLI v7.0.1 is incompatible with Node.js v6.12.0 Please upgrade Node.js to version >= 8.0.0
This is Firebase CLI (in this case, used to deploy a Firebase Hosting project), but I expect other NPM packages will start expecting higher versions of Node.js than 6.12 soon. Current Node.js LTS is 10.16.0, with end of life in 2021. Node.js 6 LTS maintenance period has ended this year.
cc @nex3 & @a14n