allocate_matrix with only a topology gives a bad error message

[KristofferC]

const grid = generate_grid(Hexahedron, (n, n, n))
const topology = ExclusiveTopology(grid)

const dh = DofHandler(grid)
const dh = DofHandler(grid)
add!(dh, :u, Lagrange{RefHexahedron, 2}()^3)
add!(dh, :p, Lagrange{RefHexahedron, 1}())
add!(dh, :q, DiscontinuousLagrange{RefHexahedron, 1}())
close!(dh)

allocate_matrix(dh; topology)

# ERROR: TypeError: in keyword argument interface_coupling, expected AbstractMatrix{Bool}, got a value of type Nothing
# Stacktrace:
#  [1] add_sparsity_entries!(sp::SparsityPattern, dh::DofHandler{…}, ch::Nothing; keep_constrained::Bool, coupling::Nothing, interface_coupling::Nothing, topology::ExclusiveTopology)