I’m attempting to create a new build configuration in Xcode in order to do a few things differently. Before I even get to that point, I’m unable to use the duplicated build configuration with no changes.

Here’s what I’m doing:

1. Project -> AppName -> Info -> Configurations
2. Click the +, Duplicate “Debug” Configuration
3. Name it whatever, I’m using “Experiment”
4. Edit the AppName Scheme -> Run -> Change Build Configuration to the newly created duplicate
5. The AppName scheme will now no longer build for running.

The errors – which vary somewhat with each attempt – all seem to indicate that the DEBUG compilation condition is not defined, but it certainly is. I’ve stripped out all the configuration sections for the Debug and Experiment build configurations from the project.pbxproj file and diffed them, and they are identical (although not in the same order, which I assume doesn’t matter).

• Xcode 15.4
• macOS 14.5