Spurious binding writability failure on nightly

[timholy]

tim@diva:~/.julia/dev/JuliaInterpreter$ ~/src/juliaw/julia --project --startup=no
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.13.0-DEV.208 (2025-03-12)
 _/ |\__'_|_|_|\__'_|  |  Commit 3e7cf64c21* (4 days old master)
|__/                   |

julia> using JuliaInterpreter

julia> bt = Base.include_string(Main, """
       ex = quote
           assignedvar = 33
           return assignedvar + 1
       end
       frame = Frame(Main, ex)
       try
           JuliaInterpreter.finish_and_return!(frame, true)
       catch
           catch_backtrace()
       end
       """);

julia> stacktrace(bt, true)
68-element Vector{Base.StackTraces.StackFrame}:
 ijl_errorf at rtutils.c:77
 ijl_check_binding_currently_writable at module.c:631
 ijl_get_binding_wr at module.c:656
 jl_f_setglobal at builtins.c:1368
 maybe_evaluate_builtin(frame::Frame, call_expr::Expr, expand::Bool) at builtins.jl:358
 evaluate_call_recurse!(recurse::Any, frame::Frame, call_expr::Expr; enter_generated::Bool) at interpret.jl:253
 evaluate_call_recurse!(recurse::Any, frame::Frame, call_expr::Expr) at interpret.jl:249
 eval_rhs(recurse::Any, frame::Frame, node::Expr) at interpret.jl:387
 step_expr!(recurse::Any, frame::Frame, node::Any, istoplevel::Bool) at interpret.jl:552
 step_expr!(recurse::Any, frame::Frame, istoplevel::Bool) at interpret.jl:612
 ⋮
 _start() at client.jl:571
 _start() at sys.so:?
 jl_apply at julia.h:2341 [inlined]
 true_main at jlapi.c:951
 jl_repl_entrypoint at jlapi.c:1111
 main at loader_exe.c:58
 ip:0x7f079c1f4d8f at libc.so.6:?
 __libc_start_main at libc.so.6:?
 _start at julia:?

julia> b = convert(Core.Binding, GlobalRef(Main, :assignedvar))
Binding Main.assignedvar
   40616:∞ - global variable with type Any
   0:40615 - undefined binding - guard entry

That ijl_check_binding_currently_writable points here.

Modifying that assignment to

global assignedvar
assignedvar = 33

doesn't fix the problem.

Any thoughts, @Keno? Here's the framecode:

julia> frame.framecode.src
CodeInfo(
    @ string:2 within `unknown scope`
1 ─     $(Expr(:globaldecl, :(Main.assignedvar)))
│       $(Expr(:latestworld))
│         builtin Core.get_binding_type(Main, :assignedvar)
│       _J1 = 33
│       _J1
│         builtin %J5 isa %J3
└──     goto #3 if not %J6
2 ─     goto #4
3 ─     _J1
└──     _J1 = Base.convert(%J3, %J9)
4 ┄     _J1
│         dynamic Base.setglobal!(Main, :assignedvar, %J11)
│   @ string:3 within `unknown scope`
│       Main.:+
│       Main.assignedvar
│         dynamic (%J13)(%J14, 1)
└──     return %J15
)

Is there something we should be doing to prepare for the assignment differently? Is it possibly a world-age issue? We don't seem to do anything with frame.world, xref #653.

[timholy]

I should add that the reason I think this probably has to do with binding partitioning is because 1.11 contains a similar check, yet on 1.11.4:

julia> using JuliaInterpreter

julia> bt = Base.include_string(Main, """
       ex = quote
           assignedvar = 33
           return assignedvar + 1
       end
       frame = Frame(Main, ex)
       try
           JuliaInterpreter.finish_and_return!(frame, true)
       catch
           catch_backtrace()
       end
       """);

julia> bt
34

which indicates that it ran without error.

[Keno]

The setglobal may need an invokelatest

[timholy]

That's a bandaid, right? Is there any way for JuliaInterpreter to bump its own task world age? If not, I guess we might assemble a list of things that need an invoke_in_world and use the frame.world. But setglobal is a good start, so I'll submit a PR.

[Keno]

JuliaInterpreter could appropriately track frame.world and invoke_in_world every potentially world-age-affected builtin.

[timholy]

Closed by #663 and #664