Compilation failure

error: proc macro panicked
 --> src/main.rs:2:1
  |
2 | typify::import_types!("./src/devContainer.base.schema.json");
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = help: message: not yet implemented: invalid (or unexpected) schema:
          {
            "description": "Indicates whether a GPU is required. The string \"optional\" indicates that a GPU is optional. An object value can be used to configure more detailed requirements.",
            "type": [
              "boolean",
              "string"
            ],
            "enum": [
              true,
              false,
              "optional"
            ]
          }

error: could not compile `foo` (bin "foo") due to 1 previous error

If you comment out https://github.com/devcontainers/spec/blob/113500f4125e0f14c9293adf4d8d94a861e0ec11/schemas/devContainer.base.schema.json#L454-L465 it compiles

Reproduce the failure from src/main.rs using typify::import_types! with the referenced devContainer.base.schema.json. Start by examining how typify handles the shown boolean/string schema with an enum, then identify the relevant compiler tests or schema fixtures. Done means the schema compiles without the proc macro panic and existing behavior remains covered by tests.