From the Macro Paradise Docs...
note the @compileTimeOnly annotation. It is not mandatory, but is recommended to avoid confusion.
Macro annotations look like normal annotations to the vanilla Scala compiler, so if you forget
to enable the macro paradise plugin in your build, your annotations will silently fail to expand.
The @compileTimeOnly annotation makes sure that no reference to the underlying definition is
present in the program code after typer, so it will prevent the aforementioned situation