Comment 0 for bug 1802312

With a snapcraft.yaml as follows:

```
name: fail-tester
version: git
version: 0.1
summary: A Snap that fails in configurable ways
description: >
  This snap is useful for testing snap hooks.

  By setting configuration on the snap, one can control which hooks will fail.

grade: devel # must be 'stable' to release into candidate/stable channels
confinement: devmode # use 'strict' once you have the right plugs and slots

parts:
```
snapcraft fails but with a strange message:

Issues while validating snapcraft.yaml: The 'parts' property does not match the required schema: <ValidationError: "None is not of type 'object'"> is not a va
lid part name. Part names consist of lower-case alphanumeric characters, hyphens, plus signs, and forward slashes. As a special case, 'plugins' is also not a
valid part name.