[BUG] OhMyREPL triggers segmentation fault in Julia 1.11

[ogauthe]

Hi! I found this code to generate a segfault when using OhMyREPL and Julia 1.11. Running with Julia 1.10 is fine.
I commented out my startup.jl, the whole code is here. Commenting the first line removes the issue.

using OhMyREPL

struct Foo end

Base.length(::Foo) = 3

struct SectorUnitRange{T,Sector,Range<:AbstractUnitRange{T}} <: AbstractUnitRange{T}
  sector::Sector
  r::Range
  offset::T

  function SectorUnitRange(s, r, offset)
    return new{eltype(r),typeof(s),typeof(r)}(s, r, offset)
  end
end

# accessors
sector(sr::SectorUnitRange) = sr.sector
Base.range(sr::SectorUnitRange) = sr.r
Base.first(sr::SectorUnitRange) = sr.offset

# Base interface
Base.length(sr::SectorUnitRange) = length(sector(sr)) * length(range(sr))

Base.iterate(sr::SectorUnitRange) = iterate(first(sr):last(sr))
Base.iterate(sr::SectorUnitRange, i::Integer) = iterate(first(sr):last(sr), i)

Base.last(sr::SectorUnitRange) = first(sr) + length(sr)

sr = SectorUnitRange(Foo(), 1:1, 3)
println("Crash here for Julia 1.11 while using OhMyREPL")
@show collect(sr)

[1843714] signal 11 (1): Segmentation fault
in expression starting at /mnt/home/ogauthe/Documents/itensor/KroneckerProducts.jl/src/minimal.jl:33
jl_gc_pool_alloc_inner at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/gc.c:1334
jl_gc_pool_alloc_noinline at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/gc.c:1391 [inlined]
jl_gc_alloc_ at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/julia_internal.h:523 [inlined]
jl_gc_alloc at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/gc.c:3951
_new_genericmemory_ at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/genericmemory.c:56 [inlined]
jl_alloc_genericmemory at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/genericmemory.c:99
GenericMemory at ./boot.jl:516 [inlined]
Array at ./boot.jl:578 [inlined]
getindex at ./array.jl:417
jl_apply at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/julia.h:2157 [inlined]
do_apply at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/builtins.c:831
most_general_argtypes at ./compiler/inferenceresult.jl:117
most_general_argtypes at ./compiler/inferenceresult.jl:115 [inlined]
matching_cache_argtypes at ./compiler/inferenceresult.jl:27
InferenceResult at ./compiler/types.jl:99 [inlined]
typeinf_ext at ./compiler/typeinfer.jl:1098
typeinf_ext_toplevel at ./compiler/typeinfer.jl:1139
typeinf_ext_toplevel at ./compiler/typeinfer.jl:1135
jfptr_typeinf_ext_toplevel_39915.1 at /mnt/home/ogauthe/.julia/juliaup/julia-1.11.3+0.x64.linux.gnu/lib/julia/sys.so (unknown line)
jl_apply at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/julia.h:2157 [inlined]
jl_type_infer at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/gf.c:390
jl_generate_fptr_impl at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/jitlayers.cpp:519
jl_compile_method_internal at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/gf.c:2536 [inlined]
jl_compile_method_internal at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/gf.c:2423
_jl_invoke at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/gf.c:2940 [inlined]
ijl_apply_generic at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/gf.c:3125
jl_apply at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/julia.h:2157 [inlined]
do_call at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/interpreter.c:126
eval_value at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/interpreter.c:223
eval_stmt_value at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/interpreter.c:174 [inlined]
eval_body at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/interpreter.c:663
jl_interpret_toplevel_thunk at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/interpreter.c:821
jl_toplevel_eval_flex at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/toplevel.c:943
jl_toplevel_eval_flex at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/toplevel.c:886
ijl_toplevel_eval_in at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/toplevel.c:994
eval at ./boot.jl:430 [inlined]
include_string at ./loading.jl:2734
_include at ./loading.jl:2794
include at ./Base.jl:557
jfptr_include_46888.1 at /mnt/home/ogauthe/.julia/juliaup/julia-1.11.3+0.x64.linux.gnu/lib/julia/sys.so (unknown line)
exec_options at ./client.jl:323
_start at ./client.jl:531
jfptr__start_73609.1 at /mnt/home/ogauthe/.julia/juliaup/julia-1.11.3+0.x64.linux.gnu/lib/julia/sys.so (unknown line)
jl_apply at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/julia.h:2157 [inlined]
true_main at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/jlapi.c:900
jl_repl_entrypoint at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/src/jlapi.c:1059
main at /cache/build/builder-demeter6-3/julialang/julia-release-1-dot-11/cli/loader_exe.c:58
__libc_start_main at /lib64/libc.so.6 (unknown line)
unknown function (ip: 0x4010b8)
Allocations: 1937142 (Pool: 1937051; Big: 91); GC: 3
Segmentation fault (core dumped)

Julia v"1.11.3"
OhMyREPL v0.5.28
additional version info:

Julia Version 1.11.3
Commit d63adeda50d (2025-01-21 19:42 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 32 × Intel(R) Xeon(R) Gold 6244 CPU @ 3.60GHz
  WORD_SIZE: 64
  LLVM: libLLVM-16.0.6 (ORCJIT, cascadelake)
Threads: 4 default, 0 interactive, 2 GC (on 32 virtual cores)
Environment:
  LD_LIBRARY_PATH = /mnt/sw/nix/store/71ksmx7k6xy3v9ksfkv5mp5kxxp64pd6-python-3.10.13-view/lib:/mnt/sw/nix/store/kkhxdzyg5kaxrxrl6j7pwapq7v7xacc7-openblas-0.3.26/lib
  JULIA_NUM_THREADS = 4

[Moelf]

it really crashed at printing, somehow, but println() doesn't crash it, display() also doesn't crash it.

[ogauthe]

it really crashed at printing, somehow, but println() doesn't crash it, display() also doesn't crash it.

Indeed. Also, adding a line @show collect(1:1) before the last line avoids the crash.

[KristofferC]

Running with bounds checking enabled I get:

julia> @show collect(sr)
ERROR: BoundsError: attempt to access 3-element Vector{Int64} at index [4]
Stacktrace:
 [1] throw_boundserror(A::Vector{Int64}, I::Tuple{Int64})
   @ Base .\essentials.jl:14
 [2] setindex!
   @ .\array.jl:986 [inlined]
 [3] Array
   @ .\range.jl:1375 [inlined]
 [4] Array
   @ .\boot.jl:605 [inlined]
 [5] collect(r::SectorUnitRange{Int64, Foo, UnitRange{Int64}})
   @ Base .\range.jl:1380
 [6] macro expansion
   @ show.jl:1232 [inlined]
 [7] top-level scope
   @ REPL[16]:1

By default you will just get memory corruption and whether it segfaults or not is unpredictable but the root cause is not OhMyREPL.

[Moelf]

By default you will just get memory corruption and whether

what does this mean -- I don't see any @inbounds in the original snippet. Normally erroring out is a lot better than segfault I think

[KristofferC]

I don't see any @inbounds in the original snippet

The @inbounds is in the collect implementation in Base. Right now, you have to get Base.length right or you risk memory corruption as shown here.

[KristofferC]

Here is the upstream issue: JuliaLang/julia#41214