ERROR: MethodError: no method matching initarray! on Julia v1.8.0-rc1

[aramirezreyes]

This issue appears on v1.8.0-rc1 so I understand if it is not a priority.
Oceananigans version: So far reproduced in v0.76.6 and v0.76.5
To reproduce, in the REPL:
The error does not prevent the fields from been created but it is a pain to do interactive work with it.

pkg> activate --temp
pkg> add NetCDF_jll@400.802.103, Oceananigans 
#NCDatasets latest release does not work with v1.8.0-rc1
julia> using Oceananigans
julia> grid = RectilinearGrid(CPU(),size = (10, 10),
                                   x = (0, 100), y = (0, 100),
                                   topology = (Periodic, Periodic, Flat), halo = (3, 3))
julia> myfield = CenterField(grid)

Outputs:

Error showing value of type Field{Center, Center, Center, Nothing, RectilinearGrid{Float64, Periodic, Periodic, Flat, Float64, Float64, Float64, OffsetArrays.OffsetVector{Float64, StepRangeLen{Float64, Base.TwicePrecision{Float64}, Base.TwicePrecision{Float64}, Int64}}, OffsetArrays.OffsetVector{Float64, StepRangeLen{Float64, Base.TwicePrecision{Float64}, Base.TwicePrecision{Float64}, Int64}}, StepRangeLen{Float64, Base.TwicePrecision{Float64}, Base.TwicePrecision{Float64}, Int64}, CPU}, Tuple{Colon, Colon, Colon}, OffsetArrays.OffsetArray{Float64, 3, Array{Float64, 3}}, Float64, FieldBoundaryConditions{BoundaryCondition{Oceananigans.BoundaryConditions.Periodic, Nothing}, BoundaryCondition{Oceananigans.BoundaryConditions.Periodic, Nothing}, BoundaryCondition{Oceananigans.BoundaryConditions.Periodic, Nothing}, BoundaryCondition{Oceananigans.BoundaryConditions.Periodic, Nothing}, Nothing, Nothing, BoundaryCondition{Oceananigans.BoundaryConditions.Flux, Nothing}}, Nothing, Oceananigans.Fields.FieldBoundaryBuffers{Nothing, Nothing, Nothing, Nothing}}:
ERROR: MethodError: no method matching initarray!(::SubArray{Float64, 3, Array{Float64, 3}, Tuple{UnitRange{Int64}, UnitRange{Int64}, UnitRange{Int64}}, false}, ::typeof(Base.add_sum), ::Bool, ::SubArray{Float64, 3, Array{Float64, 3}, Tuple{UnitRange{Int64}, UnitRange{Int64}, UnitRange{Int64}}, false})
Closest candidates are:
  initarray!(::AbstractArray{T}, ::Any, ::typeof(Base.add_sum), ::Bool, ::AbstractArray) where T at reducedim.jl:80
  initarray!(::AbstractArray{T}, ::Any, ::typeof(Base.mul_prod), ::Bool, ::AbstractArray) where T at reducedim.jl:80
  initarray!(::AbstractArray{T}, ::Any, ::Union{typeof(Base._extrema_rf), typeof(max), typeof(min)}, ::Bool, ::AbstractArray) where T at reducedim.jl:84
  ...
Stacktrace:
  [1] initialize_reduced_field!

I'm trying to figure out why would this fail in v1.8.0-rc1 but not on v1.7 but no luck so far.

[simone-silvestri]

We use that function to initialize a correct array before performing global reductions (i.e. all zeros for sums, all 1s for prods and so on...) which are called when showing a field (if you put a semicolon after myfield = CenterField(grid) the error will disappear) Apparently they have changed the signature of the function in julia-1.8. Adapting Oceananigans to the new initarray! was on the table, I guess it's a good time to fix it

[aramirezreyes]

Makes sense. I suppose it would require dropping support for v1.7?

[simone-silvestri]

Nono on 1.7 everything works fine, it's 1.8 where they changed initarray!. If possible for the moment you can work with 1.7 or 1.6, I ll fix this issue as soon as possible

[aramirezreyes]

Seems to be introduced by JuliaLang/julia#43604

[simone-silvestri]

Thanks nice observation! that helps! Then we need two initarray! methods to support both julia versions. I ll deal with it tomorrow