plan_transform fails with 3D Ultraspherical tensor product

[Jpunter16]

I am trying to construct a 3D tensor product with Ultraspherical polynomials, and I try this doing:

using ClassicalOrthogonalPolynomials
P=Ultraspherical(-0.5)
N=100
P1=plan_transform(P,(N,N,N))

but I got an error that says:

ERROR: MethodError: no method matching plan_th_ultra2ultra!(::Type{Float64}, ::Tuple{Int64, Int64, Int64}, ::Float64, ::Float64)
The function `plan_th_ultra2ultra!` exists, but no method is defined for this combination of argument types.

[dlfivefifty]

@Jpunter16 this is actually an issue in FastTransforms.jl

A work around is to apply the 2D transforms manually on matrix slices of the 3-tensor. Followed by a 1D transform on vector slices in the third direction. This would probably require making copies.