Sometimes you get better diagnostic output when executing the native executable directly from the command line (for macOS and Mac Catalyst).

The native executable is located inside the Contents/MacOS directory inside the app bundle, so if the current directory is the project directory, the full app to the executable would be something like:

# A debug build is by default in a subdirectory with the current RuntimeIdentifier:
$ ./bin/Debug/net7.0-macos/osx-x64/MyApp.app/Contents/MacOS/MyApp

# A release build is by default universal:
$ ./bin/Release/net7.0-macos/MyApp.app/Contents/MacOS/MyApp

Set the OS_ACTIVITY_DT_MODE environment variable to YES to get any output written to the system log (typically os_log or NSLog from native code) written to standard error. This is very useful when launching from the command line as explained above:

export OS_ACTIVITY_DT_MODE=Yes
$ ./bin/Debug/net7.0-macos/osx-x64/MyApp.app/Contents/MacOS/MyApp
[...]