From 59a5a7bf5f507da32afa8f866441a1e33535306e Mon Sep 17 00:00:00 2001
From: Matija Kecman <matijak@google.com>
Date: Fri, 10 Oct 2025 03:23:41 -0700
Subject: [PATCH] Improve error messages in LoadMujocoModel

PiperOrigin-RevId: 817565307
Change-Id: I367298cdf77d26b6f8deb5c6a0d5c3cab1e4d065
---
 src/experimental/toolbox/helpers.cc | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/experimental/toolbox/helpers.cc b/src/experimental/toolbox/helpers.cc
index 29700f82..aef5cea2 100644
--- a/src/experimental/toolbox/helpers.cc
+++ b/src/experimental/toolbox/helpers.cc
@@ -43,20 +43,24 @@ mjModel* LoadMujocoModel(const std::string& model_file, const mjVFS* vfs) {
   } else if (model_file.ends_with(".mjb")) {
     model = mj_loadModel(model_file.c_str(), 0);
     if (!model) {
-      mju_error("Could not load binary model");
+      mju_error("LoadMujocoModel mj_loadModel could not load file '%s'",
+                model_file.c_str());
     }
   } else if (model_file.ends_with(".xml")) {
     char error[1000] = "";
     model = mj_loadXML(model_file.c_str(), vfs, error, sizeof(error));
     if (!model) {
-      mju_error("Load model error: %s", error);
+      mju_error("LoadMujocoModel mj_loadXML failed with '%s' for file '%s'",
+                error, model_file.c_str());
     }
   } else {
     char error[1000] = "";
     auto spec =
         mj_parseXMLString(model_file.c_str(), nullptr, error, sizeof(error));
     if (!spec) {
-      mju_error("Load model error: %s", error);
+      mju_error(
+          "LoadMujocoModel mj_parseXMLString failed with '%s' for file '%s'",
+          error, model_file.c_str());
     }
     model = mj_compile(spec, 0);
     mj_deleteSpec(spec);