“Xcode errors are like horoscopes—vague but always bad.”
What version of Xcode are you using?
If you’re on Xcode 16.3, try reinstalling 16.2 instead.
I also updated from Xcode 15 to 16.3 earlier this year to support iOS SDK 18, as recommended by the App Store.
But I started encountering the same build errors you’re seeing.
Following advice from the thread below, I downgraded to Xcode 16.2, and it fixed the issue.
Xcode 16.2 uses Clang 16, while 16.3 comes with Clang 17 — and it seems like the problem stems from that compiler change.