Regression in error message for `function @main() ...`

[KristofferC]

File:

function @main()
    print("hello")
end

1.11:

❯ julia +1.11 bug.jl 
ERROR: LoadError: ParseError:
# Error @ /Users/kc/JuliaPkgs/Backporter/bug.jl:2:10

function @main()
#        └─────┘ ── Invalid signature in function definition

1.12:

❯ julia +1.12-nightly --project bug.jl
ERROR: LoadError: syntax: invalid syntax function (thismodule).main
    # /Users/kc/JuliaPkgs/Backporter/bug.jl, line 2
    # /Users/kc/JuliaPkgs/Backporter/bug.jl, line 3
    (thismodule).print("hello")
end

[topolarity]

Can you take a look please @mlechu?

[Keno]

This syntax is supposed to work now (#55040).

[Keno]

This one is pretty nasty because we can't distinguish @main and @main() in the current macro system, so if we make the former work like the latter, then the old (@main)(args) breaks.

[Keno]

@JeffBezanson points out that the non-ARGS @main doesn't work anyway, so while the error message is bad, this is low severity.