My app is failing to render under Mojave 10.14.3 when built with Xcode 10.1. It's fine under High Sierra, and it's fine if I build using Xcode 9.4.1. I THINK it was working under Mojave 10.14.2. If I transplant the 10.13 SDK from Xcode 9 to Xcode 10 and build with that, it works.
I wanted to run under OpenGL Profiler to look for OpenGL errors, but then it hangs on -[NSOpenGLContext flushBuffer].
It looks like it has to do with this change noted in the AppKit 10.14 release notes: "Windows in apps linked against the macOS 10.14 SDK are displayed using Core Animation when the app is running in macOS 10.14." I haven't figured out how to make NSOpenGLContext play nice with Core Animation.