header.labels throw an error when set on a column facet

This spec will throw an error:

{
  "data": {"url": "data/population.json"},
  "mark": "bar",
  "encoding": {
    "column": {
      "field": "sex",
      "type": "nominal",
      "header": {"title": null, "labels": false}
    },
    "y": {
      "aggregate": "sum",
      "field": "people",
      "type": "quantitative"
    },
    "x": {"field": "age", "type": "ordinal"}
  }
}

But the same on a row facet will work. And if you change labels to true, it works too.

[domoritz]

Fixed in https://github.com/vega/vega-lite/pull/6078

[domoritz]

Ahh, this is no bueno