[core] Better error message is proto is invalid.

compiler_gym/views/observation_space_spec.py

@@ -4,12 +4,11 @@
 # LICENSE file in the root directory of this source tree.
 from typing import Any, Callable, ClassVar, Optional, Union
 
-# import networkx as nx
-# import numpy as np
 from gym.spaces import Space
 
 from compiler_gym.service.proto import Event, ObservationSpace, py_converters
 from compiler_gym.util.gym_type_hints import ObservationType
+from compiler_gym.util.shell_format import indent
 
 
 class ObservationSpaceSpec:
@@ -95,10 +94,34 @@ def __eq__(self, rhs) -> bool:
 
  @classmethod
  def from_proto(cls, index: int, proto: ObservationSpace):
+ """Create an observation space from a ObservationSpace protocol buffer.
+
+ :param index: The index of this observation space into the list of
+ observation spaces that the compiler service supports.
+
+ :param proto: An ObservationSpace protocol buffer.
+
+ :raises ValueError: If protocol buffer is invalid.
+ """
+ try:
+ spec = ObservationSpaceSpec.message_converter(proto.space)
+ except ValueError as e:
+ raise ValueError(
+ f"Error interpreting description of observation space '{proto.name}'.\n"
+ f"Error: {e}\n"
+ f"ObservationSpace message:\n"
+ f"{indent(proto.space, n=2)}"
+ ) from e
+
+ # TODO(cummins): Additional validation of the observation space
+ # specification would be useful here, such as making sure that the size
+ # of {low, high} tensors for box shapes match. At present, these errors
+ # tend not to show up until later, making it more difficult to debug.
+
  return cls(
  id=proto.name,
  index=index,
- space=ObservationSpaceSpec.message_converter(proto.space),
+ space=spec,
  translate=ObservationSpaceSpec.message_converter,
  to_string=str,
  deterministic=proto.deterministic,