Rule mark not rendering

[Sean Lafferty]

@vlplot() +
@vlplot(
    data={
        values=[
            {a="A",b=28},{a="B",b=55},{a="C",b=43},
            {a="D",b=91},{a="E",b=81},{a="F",b=53},
            {a="G",b=19},{a="H",b=87},{a="I",b=52}
        ]
    },
    mark="bar",
    encoding={
        x={field="a", type="ordinal"},
        y={field="b", type="quantitative"}
    }
) + @vlplot(
	mark=:rule,
	y={datum=75},
	data={values=[{}]}
) #|> save("figure.vegalite") 

No rule is displayed. However if I save the output via uncommenting that last line, I get

{
  "layer": [
    {
      "encoding": {
        "x": {"field": "a", "type": "ordinal"},
        "y": {"field": "b", "type": "quantitative"}
      },
      "data": {
        "values": [
          {"b": 28, "a": "A"},
          {"b": 55, "a": "B"},
          {"b": 43, "a": "C"},
          {"b": 91, "a": "D"},
          {"b": 81, "a": "E"},
          {"b": 53, "a": "F"},
          {"b": 19, "a": "G"},
          {"b": 87, "a": "H"},
          {"b": 52, "a": "I"}
        ]
      },
      "mark": "bar"
    },
    {"encoding": {"y": {"datum": 75}}, "data": {"values": [{}]}, "mark": "rule"}
  ]
}

which when displayed in the vega editor, shows the rule.

[Mary McGrath]

I see this when plotting from the REPL

What version of VegaLite.jl are you using? which environment are you running it in?

[Sean Lafferty]

I'm using 1.0.0 in Pluto v0.12.17 in Julia 1.5.3 on linux

Status `~/.julia/environments/v1.5/Project.toml`
  [112f6efa] VegaLite v1.0.0

[Mary McGrath]

That's a pretty old version of VegaLite - can you upgrade?

[Sean Lafferty]

@mcmcgrath13 Ahh, sorry that did the trick :) I am new to Julia and had assumed in this cleanroom environment the most-recent version of VegaLite would have been fetched. Perhaps something peculiar with the way Pluto tried to initialize it since I used it first from within a notebook? Anyway, thanks!