fix(cli): surface a clean error on an empty or corrupt autoroute config

A configure run killed between secure_create's O_TRUNC and the write
completing leaves an empty config.yaml on disk. The next up read that
via yaml.safe_load (None) into the generated-config TypeAdapter
uncaught, surfacing a raw pydantic.ValidationError instead of pointing
the user back at `lite autoroute configure`.

litellm/proxy/client/cli/commands/autoroute/commands.py

@@ -7,7 +7,7 @@ from types import FrameType
 
 import click
 import yaml
-from pydantic import JsonValue, TypeAdapter
+from pydantic import JsonValue, TypeAdapter, ValidationError
 
 from ..up import CLAUDE_SETTINGS_PATH, load_json_or_empty, restore_claude_settings, write_backup
 from ..up import BackupRecord as ClaudeBackupRecord
@@ -46,7 +46,12 @@ def _mint_and_embed_master_key() -> str:
     """
     master_key = secrets.token_urlsafe(32)
     with open(CONFIG_PATH, "r") as f:
-        generated = _GENERATED_CONFIG_ADAPTER.validate_python(yaml.safe_load(f))
+        try:
+            generated = _GENERATED_CONFIG_ADAPTER.validate_python(yaml.safe_load(f))
+        except (yaml.YAMLError, ValidationError):
+            raise click.ClickException(
+                f"{CONFIG_PATH} is empty or corrupt. Run `lite autoroute configure` again to regenerate it."
+            )
     general_settings = generated.get("general_settings")
     updated_settings: dict[str, JsonValue] = {
         **(general_settings if isinstance(general_settings, dict) else {}),

tests/test_litellm/proxy/client/cli/autoroute/test_commands.py

@@ -56,6 +56,19 @@ class TestUpCommand:
         assert result.exit_code != 0
         assert "lite autoroute configure" in result.output
 
+    def test_surfaces_clean_error_on_empty_config_file(self, monkeypatch, tmp_path):
+        """A `configure` killed between secure_create's O_TRUNC and the write completing leaves an
+        empty config.yaml on disk -- yaml.safe_load(empty) returns None, and validating None as the
+        generated-config model raises a raw pydantic.ValidationError if uncaught."""
+        config_path, _log_path, _settings_path, _backup_path, _pid_record_path = _patch_paths(monkeypatch, tmp_path)
+        config_path.write_text("")
+
+        result = self.runner.invoke(up)
+
+        assert result.exit_code != 0
+        assert result.exception is None or isinstance(result.exception, SystemExit)
+        assert "lite autoroute configure" in result.output
+
     def test_refuses_when_pid_record_exists_and_process_still_running(self, monkeypatch, tmp_path):
         config_path, _log_path, _settings_path, _backup_path, pid_record_path = _patch_paths(monkeypatch, tmp_path)
         config_path.write_text(yaml.safe_dump({"model_list": []}))