I actually realized this is not what I wanted, because the error bar should be vertical.
For example, this looks wrong:
stairs([1,3,2,1]; label="x")
errorbars!((2:4) .- 0.5, [3,2,1], [2,3,4]; label="x")
axislegend()
current_figure()
with merge=true
I suppose one can do this manually: Makie errorbars in legend look awkward - #2 by jules