0.13: [Bug]: Spec validation error message is printed with JSON encoding

[stefreak]

Garden Bonsai (0.13) Bug

Current Behavior

When the spec.command field is not defined in an exec Test action, I currently get the following error message:

Error validating spec for Test type=exec name=foo:
[
  {
    "code": "invalid_type",
    "expected": "array",
    "received": "undefined",
    "path": [
      "command"
    ],
    "message": "Required"
  }
]

Expected behavior

I expect a human-readable error message, something like this:

Error validating spec for Test type=exec name=foo:

...
25  | type: exec
26  | name: foo
------------^
Expected an array at 'spec.command', actually received 'undefined'.

Reproducible example

Command: garden test

# garden.yml

apiVersion: garden.io/v1
kind: Project
name: foo
environments:
  - name: local

---

kind: Test
type: exec
name: foo

Workaround

Suggested solution(s)

Additional context

Your environment

• OS: macOS

garden version 0.13.20