[Bugfix] Add missing f-string prefix in xgrammar choices error message (#38162)

Signed-off-by: Yifan Zong <yzong@redhat.com>
2026-03-26 17:43:03 -04:00
parent c32e97602d
commit 28048bd6b0
1 changed files with 1 additions and 1 deletions
--- a/vllm/v1/structured_output/backend_xgrammar.py
+++ b/vllm/v1/structured_output/backend_xgrammar.py
@@ -289,7 +289,7 @@ def validate_xgrammar_grammar(sampling_params: SamplingParams) -> None:
            xgr.Grammar.from_ebnf(choice_grammar)
        except Exception as err:
            raise ValueError(
-                "Failed to transform choices into a grammar: {err}"
+                f"Failed to transform choices into a grammar: {err}"
            ) from err
        so_params.choice = None
        so_params.grammar = choice_grammar