diff --git a/App/lib/core/Gen/AssignGenMixin.vp b/App/lib/core/Gen/AssignGenMixin.vp
index 5acb69e..6db9e18 100644
--- a/App/lib/core/Gen/AssignGenMixin.vp
+++ b/App/lib/core/Gen/AssignGenMixin.vp
@@ -2254,8 +2254,10 @@ novirtual class AssignGenMixin:
 
         # Ensure the full cross-module struct definition is available (for alloca)
         self.Gen.StructGen.ensure_struct_def_in_module(pool, trans.Module, var_ty)
-        # [TEMP-DIAG] 变量声明的槽类型文本（定位完删除）：
-        #   class 标注若被解析成 `ptr`，槽就是"指针"而非值本位（`CAM: V3` / `col: V3` 现场）。
+        alloca: mlirlite.Value* = self.Gen.VarGen._alloca_at_entry(builder, var_ty)
+        # [TEMP-DIAG] 变量声明的槽类型 + **alloca 地址**（定位完删除）：
+        #   `npos = pos + Δ` 之后 pos.y 变化 ⇒ 若 pos/npos 的 slot 地址相同，说明两个变量
+        #   共用了同一块存储（槽复用/RVO 回填错槽），值语义被破坏。
         vtb: str = "?"
         bt0: str = pool.alloc_tagged(512, memhub.DETSITE_ASSIGNGEN_578)
         if bt0 is not None:
@@ -2268,8 +2270,8 @@ novirtual class AssignGenMixin:
         fn0: str = None
         if trans._cur_func is not None: fn0 = mlirlite.function_get_name(trans._cur_func)
         if fn0 is None: fn0 = "?"
-        stdio.printf("[VAR-DIAG] fn=%s name=%s vptr=%d var_ty=%s\n", fn0, nm0, vptr0, vtb)
-        alloca: mlirlite.Value* = self.Gen.VarGen._alloca_at_entry(builder, var_ty)
+        stdio.printf("[VAR-DIAG] fn=%s name=%s vptr=%d slot=0x%x var_ty=%s\n",
+                     fn0, nm0, vptr0, uint64(alloca) if alloca is not None else uint64(0), vtb)
         if alloca is not None:
             if self.Gen.VarGen.define_var(trans.SymTab, nm.id, alloca) == 0:
                 # Store the annotation's class name; pass pool so generic Subscript yields the mangled name