From 29b95e6f62e4fc07e28e6b11249a8e613ed0e83d Mon Sep 17 00:00:00 2001
From: John Chilton <jmchilton@gmail.com>
Date: Mon, 22 Dec 2025 11:44:56 -0500
Subject: [PATCH] Fix exception message to enable debugging of missing dataset
 issue.

xref https://github.com/galaxyproject/galaxy/issues/21255
---
 lib/galaxy/model/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/galaxy/model/__init__.py b/lib/galaxy/model/__init__.py
index c63830bb7f9..877b026665a 100644
--- a/lib/galaxy/model/__init__.py
+++ b/lib/galaxy/model/__init__.py
@@ -7414,7 +7414,7 @@ class DatasetCollection(Base, Dictifiable, UsesAnnotations, Serializable):
                         flush=False, element_destination=history
                     )
             else:
-                raise ValueError("Cannot replace {type(replacement.element_object)}")
+                raise ValueError(f"Cannot replace {type(replacement.element_object)}")
 
     def replace_failed_elements(self, replacements):
         stmt = self._build_nested_collection_attributes_stmt(