problem with MCMCChains.Chains() on Julia 1.7beta2

[mcreel]

chn=Chains(rand(10,2), ["a", "b"]) works fine on Julia 1.6.1, but errors on 1.7beta2

❯ ~/julia-1.7.0-beta2/bin/julia --project
_
_ _ ()_ | Documentation: https://docs.julialang.org
() | () () |
_ _ | | __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ ` | |
| | || | | | (| | | Version 1.7.0-beta2 (2021-06-20)
/ |_'|||_'_| | Official https://julialang.org/ release
|__/ |

julia> using MCMCChains

julia> chn = Chains(rand(10,2), ["α", "β"])
┌ Warning: use values(kwargs) and keys(kwargs) instead of kwargs.data and kwargs.itr
│ caller = #AxisArray#7 at core.jl:243 [inlined]
└ @ Core ~/.julia/packages/AxisArrays/IFpjG/src/core.jl:243
ERROR: type DataType has no field names
Stacktrace:
[1] getproperty(x::Type, f::Symbol)
@ Base ./Base.jl:37
[2] #s11#8
@ ~/.julia/packages/AxisAr

[devmotion]

This problem seems to be caused by AxisArrays: JuliaArrays/AxisArrays.jl#200