fixes #9600 (#9601)

compiler/vmdeps.nim

@@ -157,7 +157,10 @@ proc mapTypeToAstX(cache: IdentCache; t: PType; info: TLineInfo;
   of tyObject:
     if inst:
       result = newNodeX(nkObjectTy)
-      result.add t.sym.ast[2][0].copyTree  # copy object pragmas
+      if t.sym.ast != nil:
+        result.add t.sym.ast[2][0].copyTree  # copy object pragmas
+      else:
+        result.add newNodeI(nkEmpty, info)
       if t.sons[0] == nil:
         result.add newNodeI(nkEmpty, info)
       else:  # handle parent object

tests/macros/tgettypeinst.nim

@@ -201,3 +201,14 @@ test(MyObj):
     _ = object {.packed,myAttr,serializationKey: "one".}
       myField: int
       myField2: float
+
+block t9600:
+  type
+    Apple = ref object of RootObj
+
+  macro mixer(x: typed): untyped =
+    let w = getType(x)
+    let v = getTypeImpl(w[1])
+
+  var z: Apple
+  mixer(z)