signature fails on method with Vararg

[BioTurboNick]

julia> signature(methods(read)[12]) # read(filename::AbstractString, args...) in Base at io.jl:460
ERROR: DomainError with (Vararg{Any}, Core.TypeofVararg):
not a valid type-param
Stacktrace:
  [1] name_of_type
    @ C:\Users\nicho\.julia\packages\ExprTools\4kw5E\src\method.jl:146 [inlined]
  [2] (::ExprTools.var"#13#14")(name::Symbol, type::Core.TypeofVararg)
    @ ExprTools C:\Users\nicho\.julia\packages\ExprTools\4kw5E\src\method.jl:186
  [3] (::Base.var"#4#5"{ExprTools.var"#13#14"})(a::Tuple{Symbol, Core.TypeofVararg})
    @ Base .\generator.jl:36
  [4] iterate
    @ .\generator.jl:47 [inlined]
  [5] collect_to!(dest::Vector{Expr}, itr::Base.Generator{Base.Iterators.Zip{Tuple{Vector{Symbol}, Core.SimpleVector}}, Base.var"#4#5"{ExprTools.var"#13#14"}}, offs::Int64, st::Tuple{Int64, Int64})
    @ Base .\array.jl:842
  [6] collect_to_with_first!
    @ .\array.jl:820 [inlined]
  [7] collect(itr::Base.Generator{Base.Iterators.Zip{Tuple{Vector{Symbol}, Core.SimpleVector}}, Base.var"#4#5"{ExprTools.var"#13#14"}})
    @ Base .\array.jl:794
  [8] map
    @ .\abstractarray.jl:2981 [inlined]
  [9] arguments(m::Method, sig::Type)
    @ ExprTools C:\Users\nicho\.julia\packages\ExprTools\4kw5E\src\method.jl:184
 [10] signature(m::Method; extra_hygiene::Bool)
    @ ExprTools C:\Users\nicho\.julia\packages\ExprTools\4kw5E\src\method.jl:45
 [11] signature(m::Method)
    @ ExprTools C:\Users\nicho\.julia\packages\ExprTools\4kw5E\src\method.jl:40
 [12] top-level scope
    @ REPL[11]:1

[nickrobinson251]

which Julia version is this using?
Core.TypeofVararg in the stacktrace suggests this is post-JuliaLang/julia#38136 which i think is in v1.7+
Looks like we need a name_of_type(::TypeofVararg) method (and maybe other changes) to support this

[BioTurboNick]

Ah okay. Yeah, I was using a master source build because my usage of opaque closures segfaulted on 1.7-rc3.

[nickrobinson251]

Might be as simple as defining

if isdefined(Core, :TypeofVararg)
    name_of_type(x::Core.TypeofVararg) = x
end

🤞

I'm sure a PR would be welcome if you're happy to investigate!