Fix #10044

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

@@ -1397,7 +1397,7 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
   def desugarIdent(tree: Ident)(using Context): RefTree = {
     val qual = desugarIdentPrefix(tree)
     if (qual.isEmpty) tree
-    else qual.select(tree.symbol)
+    else atPhase(Phases.typerPhase)(qual.select(tree.symbol))
   }
 
   /** Recover identifier prefix (e.g. this) if it exists */

compiler/test-resources/repl/i10044a

@@ -0,0 +1,10 @@
+scala> object opaques { opaque type IArr[+T] = Array[_ <: T]; given arrayOps: AnyRef with { extension [T](arr: IArr[T]) { def reverse: IArr[T] = genericArrayOps(arr).reverse ; def sorted(using math.Ordering[T]): IArr[T] = genericArrayOps(arr).sorted }}}; type IArr[+T] = opaques.IArr[T] ; object IArr { inline def apply(inline x: Int, inline xs: Int*): IArr[Int] = Array(x, xs: _*).asInstanceOf }
+// defined object opaques
+// defined alias type IArr[+T] = opaques.IArr[T]
+// defined object IArr
+
+scala> IArr(1,2,3).reverse.sorted
+val res0: opaques.IArr[Int] = Array(1, 2, 3)
+
+scala> IArr(1,2,3).reverse.sorted
+val res1: opaques.IArr[Int] = Array(1, 2, 3)

compiler/test-resources/repl/i10044b

@@ -0,0 +1,12 @@
+scala> object Foo { opaque type Bar = Int ; object Bar { extension (b: Bar) def flip: Bar = -b ; def apply(x: Int): Bar = x } }
+// defined object Foo
+scala> val a = Foo.Bar(42)
+val a: Foo.Bar = 42
+scala> val b0 = a.flip
+val b0: Foo.Bar = -42
+scala> val b1 = a.flip
+val b1: Foo.Bar = -42
+scala> val c = b1.flip
+val c: Foo.Bar = 42
+scala> val d = c.flip
+val d: Foo.Bar = -42