Clean error in Xcode 11

I moved not long ago to Xcode 11 under OS 10.15. I just noticed that when I do a Clean Build Folder in Xcode 11 (since they apparently removed the Clean menu option), there are errors. I didn’t notice those before, because it doesn’t alert me to any problem unless I go to the Report Navigator. Here is what I am seeing. Any ideas? Does it matter? (It seems to build fine after this.)

> note: Using new build system
> 
> note: Building targets in parallel
> 
> error: Error while cleaning build folder, could not move '/' to '/var/folders/q1/qt7cr2490dz2txwzhq0tkdcw0000gn/T/TemporaryItems/(A Document Being Saved By XCBBuildService)/CleanBuildFolderInProgress': “10.15” couldn’t be moved to “(A Document Being Saved By XCBBuildService)”.
> 
> error: Error while cleaning build folder, could not move '/' to '/var/folders/q1/qt7cr2490dz2txwzhq0tkdcw0000gn/T/TemporaryItems/(A Document Being Saved By XCBBuildService 2)/CleanBuildFolderInProgress': “10.15” couldn’t be moved to “(A Document Being Saved By XCBBuildService 2)”.
> 
> error: Error while cleaning build folder, could not move '/' to '/var/folders/q1/qt7cr2490dz2txwzhq0tkdcw0000gn/T/TemporaryItems/(A Document Being Saved By XCBBuildService 3)/CleanBuildFolderInProgress': “10.15” couldn’t be moved to “(A Document Being Saved By XCBBuildService 3)”.