Closure not shipping to remote workers except from Main?

Consider the following code which generates a closure via an @eval (needed in my non-MWE), and then ships it to a remote worker to evaluate:

module Foo

using Distributed

make_closure(x) = @eval let x=$x; () -> x; end

function fetch_λ()
    λ = make_closure(1)
    @fetch λ()


Trying to use this, it errors with:

julia> using Distributed

julia> addprocs(1)
1-element Array{Int64,1}:

julia> using Foo

julia> Foo.fetch_λ()
ERROR: On worker 2:
UndefVarError: #3#4 not defined

However, if I switch @eval to @eval Main to eval the closure in Main, then it works. Does anyone know why this is happening and/or if its a bug?

I’m aware that globals in Main are automatically shipped to workers, but here it don’t see how that applies, since λ is a local variable inside of my fetch_λ function. Thanks for any help.