From 19ca140165cd789c12c5203a53cb81993b8879fe Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Sat, 20 Sep 2025 11:02:42 -0400
Subject: [PATCH] Improve adding model error message

---
 include/verilated.cpp                          | 12 +++++++-----
 test_regress/t/t_wrapper_reuse_context_bad.out |  2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/include/verilated.cpp b/include/verilated.cpp
index 18ab07f15..39ff67b1b 100644
--- a/include/verilated.cpp
+++ b/include/verilated.cpp
@@ -2849,11 +2849,13 @@ void VerilatedContext::addModel(const VerilatedModel* modelp) {
 
     // We look for time passing, as opposed to post-eval(), as embedded
     // models might get added inside initial blocks.
-    if (VL_UNLIKELY(time()))
-        VL_FATAL_MT(
-            "", 0, "",
-            "Adding model when time is non-zero. ... Suggest check time(), or for restarting"
-            " model use a new VerilatedContext");
+    if (VL_UNLIKELY(time())) {
+        const std::string msg
+            = "Adding model '"s + modelp->hierName()
+              + "' when time is non-zero. ... Suggest check time(), or for restarting"
+                " model use a new VerilatedContext";
+        VL_FATAL_MT("", 0, "", msg.c_str());
+    }
 
     threadPoolp();  // Ensure thread pool is created, so m_threads cannot change any more
     m_threadsInModels += modelp->threads();
diff --git a/test_regress/t/t_wrapper_reuse_context_bad.out b/test_regress/t/t_wrapper_reuse_context_bad.out
index 66e87adb9..260527d29 100644
--- a/test_regress/t/t_wrapper_reuse_context_bad.out
+++ b/test_regress/t/t_wrapper_reuse_context_bad.out
@@ -1,2 +1,2 @@
-%Error: Adding model when time is non-zero. ... Suggest check time(), or for restarting model use a new VerilatedContext
+%Error: Adding model 'TOP' when time is non-zero. ... Suggest check time(), or for restarting model use a new VerilatedContext
 Aborting...