From b245ad61528090ccad1f30a8932a93f5ebd1349a Mon Sep 17 00:00:00 2001
From: Liang-Chi Hsieh <viirya@gmail.com>
Date: Wed, 13 Dec 2023 13:58:18 -0800
Subject: [PATCH] Improve error message

---
 datafusion/expr/src/expr.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/datafusion/expr/src/expr.rs b/datafusion/expr/src/expr.rs
index 76b258a8a9e9..f0aab95b8f0d 100644
--- a/datafusion/expr/src/expr.rs
+++ b/datafusion/expr/src/expr.rs
@@ -384,8 +384,10 @@ impl ScalarFunctionDefinition {
             ScalarFunctionDefinition::UDF(udf) => {
                 Ok(udf.signature().volatility == crate::Volatility::Volatile)
             }
-            ScalarFunctionDefinition::Name(_) => {
-                internal_err!("Cannot determine volatility of unresolved function")
+            ScalarFunctionDefinition::Name(func) => {
+                internal_err!(
+                    "Cannot determine volatility of unresolved function: {func}"
+                )
             }
         }
     }
@@ -1869,6 +1871,6 @@ mod test {
         // Unresolved function
         ScalarFunctionDefinition::Name(Arc::from("UnresolvedFunc"))
             .is_volatile()
-            .expect_err("Unresolved function should not be resolved");
+            .expect_err("Shouldn't determine volatility of unresolved function");
     }
 }