Problem running Demo Closure Template and need for Java

I am trying to run the demo. I get a popup saying I need a version of Java. I’m running on a Mac 10.10.5. To investigate, I saw that the first step is to call build and that build just calls gulp. The error below indicates the problem is in not having Java. Is Java required to build this project?

becky-mac:demo peltzr$ npm run build

firebaseui@2.7.0 build /Users/peltzr/Downloads/firebaseui-web-master gulp

[12:34:26] Using gulpfile ~/Downloads/firebaseui-web-master/gulpfile.js [12:34:26] Starting ‘build-soy’… [12:34:26] Starting ‘build-css’… [12:34:26] Starting ‘build-css-rtl’… [Closure Templates Error] No Java runtime present, requesting install.

npm ERR! code ELIFECYCLE npm ERR! errno 1 npm ERR! firebaseui@2.7.0 build: gulp npm ERR! Exit status 1 npm ERR! npm ERR! Failed at the firebaseui@2.7.0 build script. npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in: npm ERR! /Users/peltzr/.npm/_logs/2018-05-02T19_34_27_023Z-debug.log becky-mac:demo peltzr$ gulp [12:34:34] Working directory changed to ~/Downloads/firebaseui-web-master [12:34:35] Using gulpfile ~/Downloads/firebaseui-web-master/gulpfile.js [12:34:35] Starting ‘build-soy’… [12:34:35] Starting ‘build-css’… [12:34:35] Starting ‘build-css-rtl’… [Closure Templates Error] No Java runtime present, requesting install.

becky-mac:demo peltzr$

[bojeil-google]

Yes, you are required to have a Java Runtime Environment. https://github.com/firebase/firebaseui-web#dependencies

[klinglt]

Same issue here while building localized firebaseUI…

$ java --version java 10.0.1 2018-04-17 Java™ SE Runtime Environment 18.3 (build 10.0.1+10) Java HotSpot™ 64-Bit Server VM 18.3 (build 10.0.1+10, mixed mode)

[14%] soy_files Compiling 3 soy files to out (0.1 sec)[Closure Templates Error] Unrecognized option: -d64 Error: Could not create the Java Virtual Machine. Error: A fatal exception has occurred. Program will exit.