I have an old program I compiled with 32-bit and 64-bit support for both Intel and PowerPC on Mac OS X 10.5, using Xcode 3.1.4. It has continued working fine all the way from 10.5 up through Mojave with no problem, other than the fact that it's not signed so users have to manually launch it the first time by right-clicking and choosing Open.
On Catalina, the NSToolbar in my main window randomly comes up as empty when I launch the program, with no way to recover other than relaunching the program.
The app works fine other than this issue. Is anyone else seeing any weird issues like this with AppKit in Catalina? Is there any reason in theory that an x86_64 app built with Xcode 3.1.4 would start having this weird glitch in Catalina?
Yes, an app compiled with an older sdk will kick in a lot of backwards compatible behaviors in AppKit. So you there could be a bug that happens only when compiling with an older sdk. I would try to compile the app with Xcode 11 and see if the issue is still there.
Thanks, you're right. It was quite a challenge converting the project from Xcode 3 to Xcode 11, but it looks like compiling it with the 10.15 SDK fixes the issue.