UndefVarError: len not defined in `make_idx(data, pair::Pair, last_val)`

julia>     x = getsimulationresultsalldata(baseline_data, treatment_data);
ERROR: UndefVarError: `len` not defined
Stacktrace:
  [1] make_idx(data::Vector{Any}, pair::Pair{String, Matrix{Float64}}, last_val::Int64)
    @ ComponentArrays ~/.julia/packages/ComponentArrays/GsPr2/src/componentarray.jl:165
  [2] make_idx(data::Vector{Any}, nt::Dict{Symbol, Pair{String}}, last_val::Int64)
    @ ComponentArrays ~/.julia/packages/ComponentArrays/GsPr2/src/componentarray.jl:157
  [3] make_carray_args(A::Type{Vector}, nt::Dict{Symbol, Pair{String}})
    @ ComponentArrays ~/.julia/packages/ComponentArrays/GsPr2/src/componentarray.jl:147
  [4] make_carray_args(nt::Dict{Symbol, Pair{String}})
    @ ComponentArrays ~/.julia/packages/ComponentArrays/GsPr2/src/componentarray.jl:139
  [5] ComponentArray(nt::Dict{Symbol, Pair{String}})
    @ ComponentArrays ~/.julia/packages/ComponentArrays/GsPr2/src/componentarray.jl:63****

im on 0.13.6
i can't show the rest of the trace but the make_idx function does look wrong

function make_idx(data, pair::Pair, last_val)
    data, ax = make_idx(data, pair.second, last_val)
    return (data, ViewAxis(last_val:(last_val+len-1), Axis(pair.second)))
end

Start in src/componentarray.jl around lines 147-165, especially the make_idx overload shown in the report. Reproduce the reported ComponentArray construction with Julia 0.13.6 and inspect how the recursive call determines the axis length. Done means the reported input no longer raises UndefVarError: len not defined.