Invalid version number in '-target arm64-apple-ios9999'

Xcode automatically updated yesterday and now I can't build my app anymore.

• Xcode version is 15.4
• clang version is 15.0.0

And when I try to run/build the app this is the error I get:

/clang:1:1 invalid version number in '-target arm64-apple-ios9999'

That's it. The weirdest part is the 9999 number there, I can't find it anywhere in the code, must be something Xcode is setting.

I tried running softwareupdate --all --install --force without success (it ended up updating my MacOS, but still same error).

Installing and running from Xcode 15.3 works just fine.

I was on Sentry 8.24.0; upgrading to 8.26.0 fixed it for me.