Converting inverse units fails

[jariji]

julia> uconvert(u"1/km", 3.0u"1/m")
ERROR: MethodError: no method matching uconvert(::Quantity{Int64, 𝐋^-1, Unitful.FreeUnits{(km^-1,), 𝐋^-1, nothing}}, ::Quantity{Float64, 𝐋^-1, Unitful.FreeUnits{(m^-1,), 𝐋^-1, nothing}})

Is this supposed to work? Why not?

[sostock]

This doesn’t work because u"1/km" is a quantity, not a unit. You can use u"km^-1" instead.

[jariji]

Thanks.

An error-message hint (Base.Experimental.register_error_hint) might be helpful here.