Confusing error message for param/variable collisions

[jamii]

Not sure exactly what's going on here, but at the very least the error message is confusing.

julia> struct Foo{T} end

julia> function test()
           types(::Foo{T}) where T = T
           T = types(Foo{Int64}())
       end
test (generic function with 1 method)

julia> test()
ERROR: UndefVarError: T not defined
Stacktrace:
 [1] types at ./REPL[10]:2 [inlined]
 [2] test() at ./REPL[10]:3
 [3] top-level scope

julia> function test2()
           types(::Foo{T}) where T = T
           T2 = types(Foo{Int64}())
       end
test2 (generic function with 1 method)

julia> test2()
Int64

[jamii]

I guess the = T is referring to the variable defined later rather than the type param defined previously? I would have expected the type param to shadow the variable.

[martinholters]

Slightly reduced:

julia> function test()
           T = 1
           foo(::Ref{T}) where T = T
       end
test (generic function with 1 method)

julia> test()(Ref(1))
ERROR: UndefVarError: T not defined

Note than one would probably expect Int to be returned (T bound to the typevar), or possibly 1 (T captured in a closure), but here it seems lowering is confused between the two. And it generates a reference to a yet undefined global:

julia> T = "global"
"global"

julia> test()(Ref(1))
"global"

I don't think that's intended.