Segfault on Turing model reduced

[mhauru]

Hi @wsmoses, as discussed on Slack, I reduced the case where the MWE of #1769 now segfaults. It's not the most minimal, and I don't think I'll have time before January to reduce it further, but it no longer depends on anything in TuringLang.

module MWE

using Distributions
using Enzyme
using Random

Random.seed!(1)

struct Metadata{
    TIdcs<:Dict{Symbol,Int},
    TVN<:AbstractVector{Symbol},
    TVal<:AbstractVector{<:Real},
}
    idcs::TIdcs
    vns::TVN
    ranges::Vector{UnitRange{Int}}
    vals::TVal
end

function Metadata()
    vals = Vector{Real}()

    return Metadata(
        Dict{Symbol,Int}(),
        Vector{Symbol}(),
        Vector{UnitRange{Int}}(),
        vals,
    )
end

function Base.push!(meta::Metadata, vn, val)
    meta.idcs[vn] = length(meta.idcs) + 1
    push!(meta.vns, vn)
    l = length(meta.vals)
    n = length(val)
    push!(meta.ranges, (l + 1):(l + n))
    append!(meta.vals, val)
    return meta
end

function replace_values(metadata::Metadata, x)
    return Metadata(
        metadata.idcs,
        metadata.vns,
        metadata.ranges,
        x,
    )
end

function data_poly(x, degree)
    return hcat([x .^ d for d in 1:degree]...)
end

# Having the third, useless argument seems significant for reproducing the segfault.
function observe(right::Distribution, left, vi)
    return Distributions.loglikelihood(right, left)
end

function model(__varinfo__)
    y = rand(Normal(0, 1), 1000)
    x = y .+ rand(Normal(0, 1.5), 1000)
    X = data_poly(x, 1)
    for i = eachindex(y)
        d2 = Normal(X[i, 1], 1.0)
        _ = observe(d2, y[i], __varinfo__)
    end
    return (0.0, __varinfo__)
end

vi = Metadata()
vn1 = :a
vi = push!(vi, vn1, 0.0)

function ldf(x)
    vi_tmp = replace_values(vi, x)
    return model(vi_tmp)
end
for i in 1:10000
    x = [randn()]
    Enzyme.gradient(Enzyme.set_runtime_activity(Enzyme.Forward), ldf, x)
end


end

Output, which seems to be indeterministic:

[63386] signal (11.2): Segmentation fault: 11
in expression starting at /Users/mhauru/projects/Enzyme-mwes/segfault_from_slowdown/mwe.jl:78
gc_mark_obj8 at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gc.c:0
gc_mark_outrefs at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gc.c:2634 [inlined]
gc_mark_loop_serial_ at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gc.c:2690
gc_mark_loop_serial at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gc.c:2713
_jl_gc_collect at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gc.c:3227
ijl_gc_collect at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gc.c:3524
maybe_collect at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gc.c:937 [inlined]
jl_gc_pool_alloc_inner at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gc.c:1293 [inlined]
ijl_gc_pool_alloc at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gc.c:1341
model at /Users/mhauru/projects/Enzyme-mwes/segfault_from_slowdown/mwe.jl:65 [inlined]
model at /Users/mhauru/projects/Enzyme-mwes/segfault_from_slowdown/mwe.jl:0 [inlined]
fwddiffejulia_model_1098_inner_1wrap at /Users/mhauru/projects/Enzyme-mwes/segfault_from_slowdown/mwe.jl:0
macro expansion at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/compiler.jl:5204 [inlined]
enzyme_call at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/compiler.jl:4750 [inlined]
ForwardModeThunk at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/compiler.jl:4638 [inlined]
runtime_generic_fwd at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/rules/jitrules.jl:303
unknown function (ip: 0x132b3c1e3)
_jl_invoke at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gf.c:0 [inlined]
ijl_apply_generic at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gf.c:3077
ldf at /Users/mhauru/projects/Enzyme-mwes/segfault_from_slowdown/mwe.jl:76 [inlined]
fwddiffejulia_ldf_390wrap at /Users/mhauru/projects/Enzyme-mwes/segfault_from_slowdown/mwe.jl:0
macro expansion at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/compiler.jl:5204 [inlined]
enzyme_call at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/compiler.jl:4750 [inlined]
ForwardModeThunk at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/compiler.jl:4638 [inlined]
autodiff at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/Enzyme.jl:654 [inlined]
autodiff at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/Enzyme.jl:524 [inlined]
macro expansion at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/sugar.jl:675 [inlined]
#gradient#126 at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/sugar.jl:577
unknown function (ip: 0x12f4d413f)
_jl_invoke at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gf.c:0 [inlined]
ijl_apply_generic at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gf.c:3077
gradient at /Users/mhauru/.julia/packages/Enzyme/haqjK/src/sugar.jl:577
top-level scope at /Users/mhauru/projects/Enzyme-mwes/segfault_from_slowdown/mwe.jl:80
jl_toplevel_eval_flex at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/toplevel.c:925
jl_eval_module_expr at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/toplevel.c:215 [inlined]
jl_toplevel_eval_flex at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/toplevel.c:736
jl_toplevel_eval_flex at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/toplevel.c:877
ijl_toplevel_eval at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/toplevel.c:943 [inlined]
ijl_toplevel_eval_in at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/toplevel.c:985
eval at ./boot.jl:385 [inlined]
include_string at ./loading.jl:2076
_jl_invoke at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gf.c:0 [inlined]
ijl_apply_generic at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gf.c:3077
_include at ./loading.jl:2136
include at ./Base.jl:495
jfptr_include_46623.1 at /Users/mhauru/.julia/juliaup/julia-1.10.6+0.aarch64.apple.darwin14/lib/julia/sys.dylib (unknown line)
_jl_invoke at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gf.c:0 [inlined]
ijl_apply_generic at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gf.c:3077
exec_options at ./client.jl:323
_start at ./client.jl:557
jfptr__start_83055.1 at /Users/mhauru/.julia/juliaup/julia-1.10.6+0.aarch64.apple.darwin14/lib/julia/sys.dylib (unknown line)
_jl_invoke at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gf.c:0 [inlined]
ijl_apply_generic at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/gf.c:3077
jl_apply at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/./julia.h:1982 [inlined]
true_main at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/jlapi.c:582
jl_repl_entrypoint at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-release-1-dot-10/src/jlapi.c:731
Allocations: 61029141 (Pool: 60977960; Big: 51181); GC: 54
Segmentation fault: 11

Enzyme v0.13.22, Julia v1.10.6.