ERROR: TypeError: in typeassert, expected Symbol, got a value of type Nothing

[jishnub]

This may be the same issue as #504, but here's a new reproducer:

julia> using LinearAlgebra

julia> D = Diagonal(fill(ones(2,2), 4));

julia> m = @which Matrix(D);

julia> Base.delete_method(m)

julia> @descend Matrix(D)
ERROR: TypeError: in typeassert, expected Symbol, got a value of type Nothing
Stacktrace:
  [1] map_signature!(sig::JuliaSyntax.TreeNode{…}, slotnames::Vector{…}, slottypes::Vector{…})
    @ TypedSyntax ~/.julia/packages/TypedSyntax/TMfzf/src/node.jl:172
  [2] map_signature!
    @ ~/.julia/packages/TypedSyntax/TMfzf/src/node.jl:118 [inlined]
  [3] JuliaSyntax.TreeNode{…}(rootnode::JuliaSyntax.SyntaxNode, src::Core.CodeInfo, mappings::Vector{…}, symtyps::IdDict{…})
    @ TypedSyntax ~/.julia/packages/TypedSyntax/TMfzf/src/node.jl:86
  [4] tsn_and_mappings(mi::Core.MethodInstance, src::Core.CodeInfo, rt::Any, sourcetext::SubString{…}, lineno::Int32; warn::Bool, strip_macros::Bool, kwargs::@Kwargs{})
    @ TypedSyntax ~/.julia/packages/TypedSyntax/TMfzf/src/node.jl:55
  [5] tsn_and_mappings(mi::Core.MethodInstance, src::Core.CodeInfo, rt::Any; warn::Bool, strip_macros::Bool, kwargs::@Kwargs{})
    @ TypedSyntax ~/.julia/packages/TypedSyntax/TMfzf/src/node.jl:39
  [6] tsn_and_mappings
    @ ~/.julia/packages/TypedSyntax/TMfzf/src/node.jl:32 [inlined]
  [7] #get_typed_sourcetext#24
    @ ~/.julia/packages/Cthulhu/MPs2i/src/reflection.jl:365 [inlined]
  [8] get_typed_sourcetext
    @ ~/.julia/packages/Cthulhu/MPs2i/src/reflection.jl:364 [inlined]
  [9] find_callsites(interp::Cthulhu.CthulhuInterpreter, CI::Core.CodeInfo, stmt_infos::Vector{…}, mi::Core.MethodInstance, slottypes::Vector{…}, optimize::Bool, annotate_source::Bool, pc2excts::Nothing)
    @ Cthulhu ~/.julia/packages/Cthulhu/MPs2i/src/reflection.jl:37
 [10] 
    @ Cthulhu ~/.julia/packages/Cthulhu/MPs2i/src/Cthulhu.jl:559
 [11] _descend(term::REPL.Terminals.TTYTerminal, interp::Cthulhu.CthulhuInterpreter, mi::Core.MethodInstance; kwargs::@Kwargs{…})
    @ Cthulhu ~/.julia/packages/Cthulhu/MPs2i/src/Cthulhu.jl:863
 [12] _descend(term::REPL.Terminals.TTYTerminal, args::Any; interp::Core.Compiler.NativeInterpreter, kwargs::@Kwargs{…})
    @ Cthulhu ~/.julia/packages/Cthulhu/MPs2i/src/Cthulhu.jl:879
 [13] __descend_with_error_handling(args::Any; terminal::Any, kwargs...)
    @ Cthulhu ~/.julia/packages/Cthulhu/MPs2i/src/Cthulhu.jl:263
 [14] _descend_with_error_handling(f::Any, argtypes::Any; kwargs::@Kwargs{iswarn::Bool})
    @ Cthulhu ~/.julia/packages/Cthulhu/MPs2i/src/Cthulhu.jl:252
 [15] descend(::Any, ::Vararg{Any}; kwargs::@Kwargs{})
    @ Cthulhu ~/.julia/packages/Cthulhu/MPs2i/src/Cthulhu.jl:306
 [16] top-level scope
    @ REPL[5]:1
Some type information was truncated. Use `show(err)` to see complete types.

julia> versioninfo()
Julia Version 1.10.5
Commit 6f3fdf7b362 (2024-08-27 14:19 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 8 × Intel(R) Core(TM) i5-10310U CPU @ 1.70GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-15.0.7 (ORCJIT, skylake)
Threads: 1 default, 0 interactive, 1 GC (on 8 virtual cores)
Environment:
  JULIA_EDITOR = subl

(@v1.10) pkg> st -m Cthulhu
Status `~/.julia/environments/v1.10/Manifest.toml`
  [f68482b8] Cthulhu v2.15.1

(@v1.10) pkg> st -m TypedSyntax
Status `~/.julia/environments/v1.10/Manifest.toml`
  [d265eb64] TypedSyntax v1.4.1

[simeonschaub]

Can you try with TypedSyntax#master? Haven't yet cut a new TypedSyntax release, will do shortly

[simeonschaub]

New version of TypedSyntax is now released, which fixes the issue for me locally. Please reopen if you still encounter an issue