cannot assign a value to variable BuiltinsNotebook.br from module workspace#41

[cormullion]

I have a weird error if I use a variable called br:

Video:

https://user-images.githubusercontent.com/52289/157880953-501fe517-4776-4720-a669-b3e32c398819.mov

Notebook:

mobius-pluto.jl.zip

I haven't tried all the two letter variable name possibilities but I have a sneaking suspicion that it's something to do with HTML...

[dralletje]

I guess it conflicts with PlutoUI.br some way

[dralletje]

Smaller example

# ╔═╡ 5919be3d-f8ce-4a0a-ab36-2d3975ca9aa9
using PlutoUI

# ╔═╡ b9bf1762-9a6a-4a78-9240-2adace14d2e2
begin
	br = 10
	for _ in a
		br
	end
end

[Pangoraw]

Smaller example

This also happens in the REPL.

In my understanding, the error should only happens if you reference the variable before the assignment. Does it have something to do with the for loop scope ?

using PlutoUI

begin
    br
    br = 1 # Fails
end

using PlutoUI

begin
    br = 1 # Succeeds
end

using PlutoUI

begin
    br = 1 # Fails but shouldn't?
    for _ in false
        br
    end
end

[Pangoraw]

Follow up issue in https://github.com/JuliaLang/julia/issues/44604

[dralletje]

@Pangoraw what an amazing find D: