Show error in @code_warntype with NamedTuple

[f-ij]

Minimal example:

mapvalues(f, nt::NamedTuple) =
    NamedTuple{keys(nt)}(f(v) for v in values(nt))

nt = (a=1,b=2)

julia> @code_warntype mapvalues(identity, a)
MethodInstance for mapvalues(::typeof(identity), ::@NamedTuple{a::Int64, b::Int64})
  from mapvalues(f, nt::NamedTuple) @ Main REPL[12]:1
Arguments
  #self#::Core.Const(Main.mapvalues)
  f::Core.Const(identity)
  nt::@NamedTuple{a::Int64, b::Int64}
Locals
  #1::var"#mapvalues##0#mapvalues##1"{typeof(identity)}
BodyERROR: BoundsError: attempt to access Core.SimpleVector at index [2]
Stacktrace:
  [1] getindex
    @ ./essentials.jl:935 [inlined]
  [2] show_at_namedtuple(io::IOContext{IOBuffer}, syms::Tuple{Symbol, Symbol}, types::DataType)
    @ Base ./show.jl:1229
  [3] show_datatype(io::IOContext{IOBuffer}, x::DataType, wheres::Vector{TypeVar})
    @ Base ./show.jl:1205
  [4] _show_type(io::IOBuffer, x::Type)
    @ Base ./show.jl:1010
  [5] show(io::IOBuffer, x::Type)
    @ Base ./show.jl:968
  [6] print(io::IOBuffer, x::Type)
    @ Base ./strings/io.jl:35
  [7] print_to_string(::String, ::Type)
    @ Base ./strings/io.jl:151
  [8] string(::String, ::Type, ::Vararg{Any})
    @ Base ./strings/io.jl:193
  [9] warntype_type_printer(io::IOContext{Base.TTY}; type::Any, used::Bool, show_type::Bool, ::@Kwargs{})
    @ InteractiveUtils ~/.julia/juliaup/julia-1.12.0+0.x64.linux.gnu/share/julia/stdlib/v1.12/InteractiveUtils/src/codeview.jl:32
 [10] print_warntype_codeinfo(io::Base.TTY, src::Core.CodeInfo, rettype::Any, nargs::Int64; lineprinter::Base.Compiler.IRShow.var"#42#43", label_dynamic_calls::Bool)
    @ InteractiveUtils ~/.julia/juliaup/julia-1.12.0+0.x64.linux.gnu/share/julia/stdlib/v1.12/InteractiveUtils/src/codeview.jl:75
 [11] code_warntype(io::Base.TTY, f::Any, tt::Any; world::UInt64, interp::Compiler.NativeInterpreter, debuginfo::Symbol, optimize::Bool, kwargs::@Kwargs{})
    @ InteractiveUtils ~/.julia/juliaup/julia-1.12.0+0.x64.linux.gnu/share/julia/stdlib/v1.12/InteractiveUtils/src/codeview.jl:171
 [12] code_warntype(io::Base.TTY, f::Any, tt::Any)
    @ InteractiveUtils ~/.julia/juliaup/julia-1.12.0+0.x64.linux.gnu/share/julia/stdlib/v1.12/InteractiveUtils/src/codeview.jl:146
 [13] code_warntype(::Any, ::Vararg{Any}; kwargs...)
    @ InteractiveUtils ~/.julia/juliaup/julia-1.12.0+0.x64.linux.gnu/share/julia/stdlib/v1.12/InteractiveUtils/src/codeview.jl:179
 [14] top-level scope
    @ REPL[16]:1

[vtjnash]

julia> err.stack[1].exception.a
svec(Vararg{Int64, N})

julia> NamedTuple{(:a, :b), Tuple{Vararg{Int, N}}} where N
@NamedTuple{a::Vararg{Int64, N}, b
Error showing value of type UnionAll:
ERROR: BoundsError: attempt to access Core.SimpleVector at index [2]