UndefVarError when a local variable is previously referenced in an @async block.

[amitmurthy]

julia> function test2()
           @async x=1
           x = 2
       end
test2 (generic function with 1 method)

julia> test2()
ERROR: UndefVarError: x not defined
 in test2 at none:2

I guess what is happening here is that x in the @async block refers to the yet-to-be-defined x in test2 ?

[samtkaplan]

For the record, here is a corresponding thread on the Julia users mailing list:
https://groups.google.com/forum/?fromgroups=#!topic/julia-users/Q5QVpry4lBI

[ihnorton]

Nominate to close, seems to be fixed on 0.5:

julia> function test2()
                 @async x=1
                 x = 2
          end
test2 (generic function with 1 method)
julia> test2()
2

The following fails (probably #13450?):

function test2()
                  @async x=1
                  println(x)
                  x = 2
end

(related? #5930)

[tkelman]

if we're going to close, should add a test

[vtjnash]

The following fails (probably #13450?):

which is as to be expected, since it has an UndefVar usage in that println (although incorrectly printed as UndefRefError, since lowering boxed it)

[amitmurthy]

Test added in #15164

Probably closed by @JeffBezanson's work on anonymous functions.