World Age problem when loading tif and multiplying result by a number

[jwscook]

I've come across a weird problem when I load a Float64 .tif file, I get a world age error and I've got no idea why. I've documented the problem in a MWE repo, FileIOWorldAgeProblem.jl. Everything about it is explained and/or shown in there.

[IanButterworth]

I believe the problem is due to FileIO being a lazy loader, where the IO packages are only loaded when you actually go to use them, and FileIO is loading the tif loader (QuartzImageIO) into Main after the module FileIOWorldAgeProblem, so has a later world age.

You're trying to use

*(::ColorTypes.Color{T,1} where T, ::Real) at /Users/james/.julia/packages/ColorVectorSpace/N6pFk/src/ColorVectorSpace.jl:223

which is provided via QuartzImageIO.ColorVectorSpace, but you're blocked from accessing it because it's too new due to the lazy loading. (FileIO overcomes this issue by using Base.invokelatest to access the newer methods that have been lazy loaded)

The likely fix would be to using ColorVectorSpace in FileIOWorldAgeProblem to ensure that the * method is loaded in that module in the same world age. And I wouldn't recommend using Base.invokelatest to fix this. Better to explicitly load things you need into the module properly

[johnnychen94]

Maybe we should document this as an expected behavior somewhere?