(spurious?) global binding world age warning involving function that returns a huge tuple

[nsajko]

EDIT: see simpler reproducer below

julia> for i ∈ 1:100
           n = 2^i
           @eval g() = ntuple(Returns(nothing), Val($n))
           eff = Base.infer_effects(g, Tuple{})
           display(eff)
       end
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
(+c,+e,+n,+t,+s,+m,+u,+o,+r)
WARNING: Detected access to binding `Base.string` in a world prior to its definition world.
  Julia 1.12 has introduced more strict world age semantics for global bindings.
  !!! This code may malfunction under Revise.
  !!! This code will error in future versions of Julia.
Hint: Add an appropriate `invokelatest` around the access to this binding.
(!c,+e,!n,!t,+s,+m,!u,+o,+r)
(!c,+e,!n,!t,+s,+m,!u,+o,+r)
(!c,+e,!n,!t,+s,+m,!u,+o,+r)
[...]

@Keno

[nsajko]

This is with latest nightly assert build, version info:

Julia Version 1.13.0-DEV.15
Commit b65f0040dd3 (2025-02-07 05:08 UTC)
Build Info:
  Official https://julialang.org release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 8 × AMD Ryzen 3 5300U with Radeon Graphics
  WORD_SIZE: 64
  LLVM: libLLVM-18.1.7 (ORCJIT, znver2)
  GC: Built with stock GC
Threads: 1 default, 1 interactive, 1 GC (on 8 virtual cores)

[nsajko]

Simpler reproducer:

julia> g() = ntuple(Returns(nothing), Val(1000000))
g (generic function with 1 method)

julia> Base.infer_effects(g, Tuple{})
WARNING: Detected access to binding `Base.string` in a world prior to its definition world.
  Julia 1.12 has introduced more strict world age semantics for global bindings.
  !!! This code may malfunction under Revise.
  !!! This code will error in future versions of Julia.
Hint: Add an appropriate `invokelatest` around the access to this binding.
(!c,+e,!n,!t,+s,+m,!u,+o,+r)

[nsajko]

Maybe something to do with bootstrapping and Compiler/src/ssair/show.jl? I see that file uses string, even though string is defined after Compiler AFAIK. At the top of the file it says this:

julia/Compiler/src/ssair/show.jl

Lines 3 to 5 in b65f004

	# This file does not participate in bootstrapping, but is included in the system image by
	# being loaded from `base/show.jl`. Compiler.jl as the standard library will simply include
	# this file in the context of `Compiler.IRShow`.

[nsajko]

Seems to happen within Compiler.typeinf_local. Is there a way to pinpoint from where exactly the warning is printed? Reproducer for debugger:

f() = ntuple(Returns(nothing), Val(1000000))
using Compiler: Compiler
atypes = Tuple{}
m = only(methods(f, atypes))
interp = Compiler.NativeInterpreter()
sparams = Core.svec()
types = Tuple{typeof(f), atypes.parameters...}
using Debugger: Debugger
Debugger.@enter Compiler.typeinf_type(interp, m, types, sparams)

[vtjnash]

It is an implementation translation mistake #57230, combined with being forbidden from making expressions with more than 520k statements. It does not break execution since there is a correct fallback for the generated ntuple

790             if (jl_expr_nargs(ex) > 520000 && ex->head != jl_block_sym)
791                 lerror(fl_ctx, symbol(fl_ctx, "error"), "expression too large");

$ ./julia -e 'code_lowered(ntuple, (Returns{Nothing}, Val{1000000}))'
WARNING: Detected access to binding `Base.string` in a world prior to its definition world.
  Julia 1.12 has introduced more strict world age semantics for global bindings.
  !!! This code may malfunction under Revise.
  !!! This code will error in future versions of Julia.
Hint: Add an appropriate `invokelatest` around the access to this binding.
ERROR: MethodError: no method matching string(::String, ::String)
The applicable method may be too new: running in world age 6110, while current world is 38517.
Stacktrace:
 [1] generated_body_to_codeinfo(ex::Expr, defmod::Module, isva::Bool)
   @ Base ./expr.jl:1675
 [2] (::Core.GeneratedFunctionStub)(::UInt64, ::Method, ::Any, ::Vararg{Any})
   @ Base ./expr.jl:1708