display() is not defined warning

[nblomberg]

While using backend PyPlot you get warning on the first run "_display is not defined for this backend." when pyplot() is inside a function. I don't know if this how it is intended to work, but at least the warning could be more helpful. I have no idea why it has problems with display in particular?

using Plots

function main()
    pyplot()
    a = plot(1:10,1:10)
    display(a)
end
main()

This works fine if pyplot() is outside of main().

[BeastyBlacksmith]

Note that the following works

using Plots

function main()
    pyplot()
    plot(1:10,1:10)
end
p = main()
display(p)

But you need to return to the toplevel between a backend switch and the display, since the backend initialization is in a different world age otherwise

[BeastyBlacksmith]

A second option is to use Base.invokelatest

using Plots

function main()
    pyplot()
    p = plot(1:10,1:10)
    Base.invokelatest(display, p)
end