Mixed type, variable length, memcpy

[jgreener64]

I am on Julia 1.10.3 and Enzyme main (5fc2309). The following works:

struct A1{T}
    x::T
end

struct B{T}
    as::T
end

function f1(x, ::Val{AT}) where AT
    as = [A1(x) for i in 1:10]
    as2 = AT(as)
    b = B(as2)
    return b.as[1].x
end

autodiff(Reverse, f1, Active, Active(2.0), Const(Val(Array)))[1][1] # Gives 1.0

However, adding an unused field to the struct makes the gradient disappear:

struct A2{T}
    index::Int
    x::T
end

function f2(x, ::Val{AT}) where AT
    as = [A2(i, x) for i in 1:10]
    as2 = AT(as)
    b = B(as2)
    return b.as[1].x
end

autodiff(Reverse, f2, Active, Active(2.0), Const(Val(Array)))[1][1] # Gives 0.0, should be 1.0