For a verification job like our use of Github Actions is used as, we need to better control the build environment to avoid surprises. For Macos, Github current provides two different images, macos-10.15 and macos-latest. The latest is a moving target and because of that, I don't think it should be used. The image also comes with a whole range of different Xcode versions. Here we need to pick one we know works and stick with it. At Oracle we are currently using 11.3.1 so I would suggest sticking with the same version to avoid discrepancies.