Found the issue - it’s a bug in GWS 2.0.1. It’s not a missing resource at all, but rather a Java version mismatch.
I originally installed 2.0.1 so I could use it on Mac OS Big Sur, but it’s too broken. So I installed 2.0.0 on an older Mac running High Sierra and got the proper error when I tried to build. Turns out it’s a Java issue.
I had to uninstall JDK 17 and dig up and install JDK 14.0.2. Now it works!