I made a double post. Please post your reply in the newer thread. To moderators: please delete this if there are no other replies.

Similar results were obtained with the following sample that does not use SDL: https://github.com/kanjitalk755/Metal-simple-sample

In my case, in Xcode 16 or later, I open the project and reproduce it on the second and subsequent RUNs. This phenomenon did not exist until Xcode 15.4. Check the run scheme's "Options" setting for "Console". This setting opens a window that displays the normal log, and a separate window that runs for a short time and then quits. Does anyone know how to fix it?

I found a workaround in the case of a Command Line Tool which opens a window with SDL2. Create an App project. However, main() does not call NSApplicationMain(). "-NSDocumentRevisionsDebugMode" and "YES" are passed to argv, so ignore them.