XCode 26 beta 4 Playground macro issue

Using the #Playground macro in beta 3 worked fine, but the Playgrounds package appears to be missing in beta 4.

import Playgrounds

#Playground {
    print("🚀 Playground is active")
}

Canvas error message:

Cannot find playgrounds

Check whether the playground is compiled for the current scheme and OS of the selected device. There could be compile time checks filtering playgrounds out. Check for dead code stripping or other settings that could exclude playgrounds from the final binary.