StackOverflow in type inference

[jrevels]

This is a pretty nifty one that @andreasnoack ran into. Probably related to #20103, but doesn't seem exactly the same.

To reproduce, checkout JuliaStats/Distributions.jl@3e8d9f9 and JuliaDiff/ForwardDiff.jl@791cd93 (at the time of writing, these are both the head of the master branches of these packages).

Then, run the following:

julia> using Distributions

julia> using ForwardDiff

julia> tmp1 = vcat([1,1], 1, 1)
WARNING: An error occurred during inference. Type inference is now partially disabled.
StackOverflowError()
intersect at /Users/jarrettrevels/data/repos/julia6/src/subtype.c:1626
intersect_ufirst at /Users/jarrettrevels/data/repos/julia6/src/subtype.c:1032 [inlined]
intersect_var at /Users/jarrettrevels/data/repos/julia6/src/subtype.c:1100
intersect at /Users/jarrettrevels/data/repos/julia6/src/subtype.c:1626
intersect_ufirst at /Users/jarrettrevels/data/repos/julia6/src/subtype.c:1032 [inlined]
intersect_var at /Users/jarrettrevels/data/repos/julia6/src/subtype.c:1100
intersect at /Users/jarrettrevels/data/repos/julia6/src/subtype.c:1626
⋮ # stacktace repeats for a while until it bubbles back up out of the recursion
4-element Array{Int64,1}:
 1
 1
 1
 1

The best part is that this bug can be circumvented by commenting out Base.zero and Base.one definitions on lines 132 and 135 here.

versioninfo:

julia> versioninfo()
Julia Version 0.6.0-dev.2478
Commit dbf41c0 (2017-01-30 18:58 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin13.4.0)
  CPU: Intel(R) Core(TM) i5-4288U CPU @ 2.60GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
  LAPACK: libopenblas64_
  LIBM: libopenlibm
  LLVM: libLLVM-3.9.1 (ORCJIT, haswell)

[andreasnoack]

FWIW 93a725d caused this.

[mlubin]

I also see a similar error on this branch of JuMP. At the moment this is blocking me from doing any more work on JuMP compatibility with 0.6.

[tkelman]

I get a similar error from Pkg.test("BaseBenchmarks") on current master of that (and branch tk/drop0.4 of FileIO)

[andreasnoack]

@JeffBezanson This was broken by 93a725d, i.e. the commit that fixed JuliaLang/LinearAlgebra.jl#399

[JeffBezanson]

See how far #20448 gets you.