fix(build_config): validation when NoneType

src/bentoml/_internal/bento/build_config.py

@@ -638,13 +638,15 @@ def _python_options_structure_hook(d: t.Any, _: t.Type[PythonOptions]) -> Python
 
 
 if TYPE_CHECKING:
-    OptionsCls = t.Union[DockerOptions, CondaOptions, PythonOptions]
+    OptionsCls = DockerOptions | CondaOptions | PythonOptions
 
 
 def dict_options_converter(
     options_type: t.Type[OptionsCls],
-) -> t.Callable[[t.Union[OptionsCls, t.Dict[str, t.Any]]], t.Any]:
-    def _converter(value: t.Union[OptionsCls, t.Dict[str, t.Any]]) -> options_type:
+) -> t.Callable[[OptionsCls | dict[str, t.Any]], t.Any]:
+    def _converter(value: OptionsCls | dict[str, t.Any]) -> options_type:
+        if value is None:
+            return options_type()
         if isinstance(value, dict):
             return options_type(**value)
         return value
@@ -673,18 +675,38 @@ class BentoBuildConfig:
     include: t.Optional[t.List[str]] = None
     exclude: t.Optional[t.List[str]] = None
     docker: DockerOptions = attr.field(
-        factory=DockerOptions,
+        default=None,
         converter=dict_options_converter(DockerOptions),
     )
     python: PythonOptions = attr.field(
-        factory=PythonOptions,
+        default=None,
         converter=dict_options_converter(PythonOptions),
     )
     conda: CondaOptions = attr.field(
-        factory=CondaOptions,
+        default=None,
         converter=dict_options_converter(CondaOptions),
     )
 
+    if TYPE_CHECKING:
+
+        # NOTE: This is to ensure that BentoBuildConfig __init__
+        # satisfies type checker. docker, python, and conda accepts
+        # dict[str, t.Any] since our converter will handle the conversion.
+        # There is no way to tell type checker signatures of the converter from attrs
+        # if given attribute is alrady has a type annotation.
+        def __init__(
+            self,
+            service: str,
+            description: str | None = ...,
+            labels: dict[str, t.Any] | None = ...,
+            include: list[str] | None = ...,
+            exclude: list[str] | None = ...,
+            docker: DockerOptions | dict[str, t.Any] | None = ...,
+            python: PythonOptions | dict[str, t.Any] | None = ...,
+            conda: CondaOptions | dict[str, t.Any] | None = ...,
+        ) -> None:
+            ...
+
     def __attrs_post_init__(self) -> None:
         use_conda = not self.conda.is_empty()
         use_cuda = self.docker.cuda_version is not None
@@ -715,6 +737,10 @@ def __attrs_post_init__(self) -> None:
                         )
 
                 if self.docker.cuda_version is not None:
+                    if _spec.supported_cuda_versions is None:
+                        raise BentoMLException(
+                            f"{self.docker.distro} does not support CUDA, while 'docker.cuda_version={self.docker.cuda_version}' is provided."
+                        )
                     if self.docker.cuda_version != "default" and (
                         self.docker.cuda_version not in _spec.supported_cuda_versions
                     ):