Hack, but does not work

Author: SolalPirelli

compiler/src/dotty/tools/dotc/ast/Desugar.scala

@@ -406,7 +406,7 @@ object desugar {
     def paramssNoRHS = mapParamss(meth.paramss)(identity) {
       vparam =>
         if vparam.rhs.isEmpty then vparam
-        else cpy.ValDef(vparam)(rhs = EmptyTree).withMods(vparam.mods | HasDefault)
+        else cpy.ValDef(vparam)(/*rhs = EmptyTree*/).withMods(vparam.mods | HasDefault)
     }
 
     def getterParamss(n: Int): List[ParamClause] =

compiler/src/dotty/tools/dotc/transform/PostTyper.scala

@@ -229,7 +229,9 @@ class PostTyper extends MacroTransform with InfoTransformer { thisPhase =>
       Checking.checkValidOperator(sym)
       sym.transformAnnotations(transformAnnot)
       sym.defTree = tree
-      tree
+      tree match
+        case v: ValDef if v.mods.is(HasDefault) => cpy.ValDef(v)(rhs = EmptyTree).asInstanceOf[tree.type]
+        case _ => tree
     }
 
     private def registerIfUnrolledParam(sym: Symbol)(using Context): Unit =