misc: Improve llava error messages

Author: abetlen

llama_cpp/llama_chat_format.py

@@ -2642,13 +2642,13 @@ def embed_image_bytes(image_bytes: bytes):
             if type_ == "text":
                 tokens = llama.tokenize(value.encode("utf8"), add_bos=False, special=True)
                 if llama.n_tokens + len(tokens) > llama.n_ctx():
-                    raise ValueError("Prompt exceeds n_ctx") # TODO: Fix
+                    raise ValueError(f"Prompt exceeds n_ctx: {llama.n_tokens + len(tokens)} > {llama.n_ctx()}")
                 llama.eval(tokens)
             else:
                 image_bytes = self.load_image(value)
                 embed = embed_image_bytes(image_bytes)
                 if llama.n_tokens + embed.contents.n_image_pos > llama.n_ctx():
-                    raise ValueError("Prompt exceeds n_ctx") # TODO: Fix
+                    raise ValueError(f"Prompt exceeds n_ctx: {llama.n_tokens + embed.contents.n_image_pos} > {llama.n_ctx()}")
                 n_past = ctypes.c_int(llama.n_tokens)
                 n_past_p = ctypes.pointer(n_past)
                 with suppress_stdout_stderr(disable=self.verbose):