Unreachable reached - Linux and Windows - Julia v1.0.1 and 0.7.0

[mohamed82008]

Hi,

The following code seems to break multiple versions of Julia. I tried it on Linux and Windows, v0.7.0 and v1.0.1. It worked fine in Julia v0.6.4.

run(`git clone https://github.com/mohamed82008/TopOpt.jl TopOpt`)
cd(()->run(`git checkout segfault`), "TopOpt")
using Pkg
Pkg.activate("./TopOpt")
Pkg.instantiate()

include("TopOpt/test/segfault.jl")

Here is the Linux versioninfo():

Julia Version 1.0.1
Commit 0d713926f8 (2018-09-29 19:05 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-6.0.0 (ORCJIT, skylake)

Good luck!

[mohamed82008]

Since the fix for this bug may take some time, I would appreciate any tip to work around it as it is currently a show stopper for using v1.0 in my work. Thank you.

[vchuravy]

For reference, with an assertion build.

Unreachable reached at 0x7f82c930ba0d

signal (4): Illegal instruction
in expression starting at /tmp/TopOpt/test/segfault.jl:7
Type at ./none:0
Type at ./none:0
unknown function (ip: 0x7f82c930b875)
jl_fptr_trampoline at /home/vchuravy/src/julia/src/gf.c:1854
jl_apply_generic at /home/vchuravy/src/julia/src/gf.c:2209
do_call at /home/vchuravy/src/julia/src/interpreter.c:323
eval_value at /home/vchuravy/src/julia/src/interpreter.c:411
eval_stmt_value at /home/vchuravy/src/julia/src/interpreter.c:362 [inlined]
eval_body at /home/vchuravy/src/julia/src/interpreter.c:753
jl_interpret_toplevel_thunk_callback at /home/vchuravy/src/julia/src/interpreter.c:883
unknown function (ip: 0xfffffffffffffffe)
unknown function (ip: 0x7f82ab6b28ff)
unknown function (ip: 0x7)
jl_interpret_toplevel_thunk at /home/vchuravy/src/julia/src/interpreter.c:892
jl_toplevel_eval_flex at /home/vchuravy/src/julia/src/toplevel.c:764
jl_toplevel_eval_flex at /home/vchuravy/src/julia/src/toplevel.c:713
jl_parse_eval_all at /home/vchuravy/src/julia/src/ast.c:883
jl_load at /home/vchuravy/src/julia/src/toplevel.c:826
include at ./boot.jl:317 [inlined]
include_relative at ./loading.jl:1038
include at ./sysimg.jl:29
jl_apply_generic at /home/vchuravy/src/julia/src/gf.c:2209
include at ./client.jl:392
jl_fptr_trampoline at /home/vchuravy/src/julia/src/gf.c:1854
jl_apply_generic at /home/vchuravy/src/julia/src/gf.c:2209
do_call at /home/vchuravy/src/julia/src/interpreter.c:323
eval_value at /home/vchuravy/src/julia/src/interpreter.c:411
eval_stmt_value at /home/vchuravy/src/julia/src/interpreter.c:362 [inlined]
eval_body at /home/vchuravy/src/julia/src/interpreter.c:753
jl_interpret_toplevel_thunk_callback at /home/vchuravy/src/julia/src/interpreter.c:883
unknown function (ip: 0xfffffffffffffffe)
unknown function (ip: 0x7f82cf00b4df)
unknown function (ip: 0xffffffffffffffff)
jl_interpret_toplevel_thunk at /home/vchuravy/src/julia/src/interpreter.c:892
jl_toplevel_eval_flex at /home/vchuravy/src/julia/src/toplevel.c:764
jl_toplevel_eval_in at /home/vchuravy/src/julia/src/toplevel.c:793
eval at ./boot.jl:319
jl_apply_generic at /home/vchuravy/src/julia/src/gf.c:2209
eval_user_input at /home/vchuravy/builds/julia/usr/share/julia/stdlib/v1.1/REPL/src/REPL.jl:85
macro expansion at /home/vchuravy/builds/julia/usr/share/julia/stdlib/v1.1/REPL/src/REPL.jl:117 [inlined]
#26 at ./task.jl:259
jl_apply_generic at /home/vchuravy/src/julia/src/gf.c:2209
jl_apply at /home/vchuravy/src/julia/src/julia.h:1571 [inlined]
start_task at /home/vchuravy/src/julia/src/task.c:572
unknown function (ip: 0xffffffffffffffff)
Allocations: 52499071 (Pool: 52490987; Big: 8084); GC: 113
fish: “~/builds/julia/julia” terminated by signal SIGILL (Illegal instruction)

versioninfo()
Julia Version 1.1.0-DEV.595
Commit c2bda2c4de* (2018-11-01 17:49 UTC)

[JeffBezanson]

I believe I've reduced it to this:

julia> struct MMAModel{T, TV<:AbstractVector{T}}
       end

julia> typeintersect(MMAModel, MMAModel{<:Any,TV} where TV>:Vector{Float64})
Union{}

[JeffBezanson]

Another one:

julia> struct A29955{T, TV<:AbstractVector{T}, TModel<:MMAModel{T,TV}}
       end

julia> typeintersect(Tuple{Type{A29955{Float64,Array{Float64,1},_1}} where _1,
                           Any},
                     Tuple{Type{A29955{T,TV,TM}},
                           TM} where {T,TV<:AbstractVector{T},TM<:MMAModel{T,TV}})
Union{}

[JeffBezanson]

Turns out to be related to this interesting case:

julia> struct M29955{T, TV<:AbstractVector{T}}
       end

julia> M29955{T,Vector{Float64}} where T
ERROR: TypeError: in M29955, in TV, expected TV<:AbstractArray{T,1}, got Type{Array{Float64,1}}

That should probably be allowed.

[mohamed82008]

Thanks!