Namespacing confusion: `uparse("myMeter")` example from docs gives ArgumentError

```julia
using Unitful
module MyUnits; using Unitful; @unit myMeter "m" MyMeter 1u"m" false; end
Unitful.register(MyUnits);
u"myMeter" # works

julia> uparse("myMeter")
ERROR: ArgumentError: Symbol `myMeter` was found in the globally registered unit module Main.MyUnits
but was not in the provided list of unit modules Unitful.

(Consider `using Main.MyUnits` in your module if you are using `@u_str`?)
Stacktrace:
[1] lookup_units(unitmods::Vector{Module}, sym::Symbol)
@ Unitful ~\.julia\packages\Unitful\PcVKX\src\user.jl:575
[2] lookup_units
@ ~\.julia\packages\Unitful\PcVKX\src\user.jl:593 [inlined]
[3] uparse(str::String; unit_context::Module)
@ Unitful ~\.julia\packages\Unitful\PcVKX\src\user.jl:536
[4] uparse(str::String)
@ Unitful ~\.julia\packages\Unitful\PcVKX\src\user.jl:535
[5] top-level scope
@ REPL[31]:1
using Main.MyUnits
uparse("myMeter") # still fails
```

```julia
using Unitful
Unitful.register(@__MODULE__);
@unit U "U" U 1u"μmol/60s" true
1u"U"
uparse("U") # fails
ERROR: ArgumentError: Symbol `U` was found in the globally registered unit module Mainbut was not in the provided list of unit modules Unitful.

(Consider `using Main` in your module if you are using `@u_str`?)
using Main
uparse("U") # still fails
```
There may be a problem with `uparse` or I am not understanding namespacing. It is confusing to me why neither examples can be copy pasted to REPL