Missing tokenizer.model error during gguf conversion (ggerganov#6443)

Co-authored-by: Jared Van Bortel <[email protected]>

convert-hf-to-gguf.py

@@ -323,8 +323,7 @@ def _set_vocab_sentencepiece(self):
         toktypes: list[int] = []
 
         if not tokenizer_path.is_file():
-            print(f'Error: Missing {tokenizer_path}', file=sys.stderr)
-            sys.exit(1)
+            raise FileNotFoundError(f"File not found: {tokenizer_path}")
 
         tokenizer = SentencePieceProcessor(str(tokenizer_path))
         vocab_size = self.hparams.get('vocab_size', tokenizer.vocab_size())