Ah, thanks!
The builds should be back up and running. The issue wasn’t hardware–the build VM was based on 10.14, and you can no longer install OpenCascade through Homebrew on 10.14. Creating a 10.15 VM and adjusting the notarization process took a few days.
If you’re interested in learning the nitty-gritty of building and packaging non-Xcode-based cross-platform macOS apps, let me know! I might be a little busy until 6 comes out, but I’d love to get some folks helping soon enough!