Avast detects trojan in Xcode Previews

I’m completely new to Xcode. It apparently has a subsystem called Xcode Previews that allows visual debugging.
I reported the following to Apple, they came back with “Gee, can you ask Avast about that?”
So, here goes:
The MacOS executable for Xcode Previews is normally 174K. Using Time Machine I find it has always been so.
Avast now removes that executable to it’s “Virus Chest”.
I restore it from Time Machine to a temp directory and re-run Avast on it it finds it again. I’m not actually using Xcode Previews as far as I know, my simple apps (not SwiftUI etc) still compile and run.
But that app now has no MacOS executable file.