Assert the text embeddings process successfully runs

threestudio/models/prompt_processors/base.py

@@ -379,6 +379,7 @@ def prepare_text_embeddings(self):
                 )
                 subprocess.start()
                 subprocess.join()
+                assert subprocess.exitcode == 0, "prompt embedding process failed!"
             else:
                 self.spawn_func(
                     self.cfg.pretrained_model_name_or_path,