(Sorry - I clicked the Accepted Answer by mistake and can't undo it? Comments are not being posted either - they come back with an error.)

Hi Quinn, we're using the inbuilt compilers. It all worked with XCode pre-16.4/26 then stopped after updating XCode and rebuilding the app. It took me a frustrating 2 days to work out that was the problem as it was somewhat obscure. Note that it builds and runs, but fails to perform the initialisation on library load.

Hi Quinn, we are using the inbuilt compiler.

Hi Quinn, we are using the inbuilt compiler. (FYI - it all worked on my earlier XCode 16 but stopped when I bought an iPhone 17, when found I had to upgrade to Xcode 26, then MacOS 26, then also found I could install XCode 16.4 so the project configuration wasn't confused between 16.4 and 26 amongst the team who hadn't yet migrated to Tahoe or iOS 26).

Hi Quinn, we are using the inbuilt compiler. (FYI - it all worked on my earlier XCode 16 but stopped when I bought an iPhone 17, when found I had to upgrade to Xcode 26, then MacOS 26, then also found I could install XCode 16.4 so the project configuration wasn't confused between 16.4 and 26 amongst the team who hadn't yet migrated to Tahoe or iOS 26).