Current version of ApproxFun.LowRankFun causes fatal error in 0.5.1, segfault in 0.6.0-pre.beta.9 and StackOverflowError in 0.6.0-pre.beta.50

[ikirill]

With a clean ~/.julia, and Pkg.add("ApproxFun") followed by Pkg.checkout("ApproxFun"), I get the following errors.

On

julia> versioninfo()
Julia Version 0.6.0-pre.beta.50
Commit d5d728024f (2017-04-06 20:20 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin13.4.0)
  CPU: Intel(R) Core(TM) i7-4770HQ CPU @ 2.20GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
  LAPACK: libopenblas64_
  LIBM: libopenlibm
  LLVM: libLLVM-3.9.1 (ORCJIT, haswell)

I get:

julia> using ApproxFun
INFO: Recompiling stale cache file /Users/kirill/.julia/lib/v0.6/ApproxFun.ji for module ApproxFun.

julia> LowRankFun((x,y) -> x*y, 0.0..1.0, 0.0..1.0)
ERROR: StackOverflowError:
Stacktrace:
 [1] ApproxFun.LowRankFun(::Function, ::IntervalSets.ClosedInterval{Float64}, ::IntervalSets.ClosedInterval{Float64}) at /Users/kirill/.julia/v0.6/ApproxFun/src/Multivariate/LowRankFun.jl:184
 [2] #LowRankFun#194(::Array{Any,1}, ::Type{T} where T, ::Function, ::IntervalSets.ClosedInterval{Float64}, ::Vararg{IntervalSets.ClosedInterval{Float64},N} where N) at /Users/kirill/.julia/v0.6/ApproxFun/src/Multivariate/LowRankFun.jl:184
 [3] ApproxFun.LowRankFun(::Function, ::IntervalSets.ClosedInterval{Float64}, ::IntervalSets.ClosedInterval{Float64}) at /Users/kirill/.julia/v0.6/ApproxFun/src/Multivariate/LowRankFun.jl:184
 [4] #LowRankFun#194(::Array{Any,1}, ::Type{T} where T, ::Function, ::IntervalSets.ClosedInterval{Float64}, ::Vararg{IntervalSets.ClosedInterval{Float64},N} where N) at /Users/kirill/.julia/v0.6/ApproxFun/src/Multivariate/LowRankFun.jl:184
.....

(this repeats, 21373 lines in total, not posted)

On

julia> versioninfo()
Julia Version 0.6.0-pre.beta.9
Commit ceb06740e3 (2017-04-02 01:04 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin13.4.0)
  CPU: Intel(R) Core(TM) i7-4770HQ CPU @ 2.20GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
  LAPACK: libopenblas64_
  LIBM: libopenlibm
  LLVM: libLLVM-3.9.1 (ORCJIT, haswell)

I get

julia> using ApproxFun
INFO: Precompiling module ApproxFun.

julia> LowRankFun((x,y) -> x*y, 0.0..1.0, 0.0..1.0)
Segmentation fault: 11

and with

julia> versioninfo()
Julia Version 0.5.1
Commit 6445c82 (2017-03-05 13:25 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin13.4.0)
  CPU: Intel(R) Core(TM) i7-4770HQ CPU @ 2.20GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
  LAPACK: libopenblas64_
  LIBM: libopenlibm
  LLVM: libLLVM-3.7.1 (ORCJIT, haswell)

I get

julia> using ApproxFun

julia> LowRankFun((x,y) -> x*y, 0.0..1.0, 0.0..1.0)
fatal: error thrown and no exception handler available.
ErrorException("task switch not allowed from inside gc finalizer")
rec_backtrace at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/stackwalk.c:84
record_backtrace at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/task.c:233 [inlined]
jl_throw at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/task.c:551
jl_error at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/builtins.c:42
jl_switchto at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/task.c:397
yieldto at ./event.jl:136
jlcall_yieldto_23447 at /opt/Julia-0.5.app/Contents/Resources/julia/lib/julia/sys.dylib (unknown line)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:210 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1950
wait at ./event.jl:169
task_done_hook at ./task.jl:191
unknown function (ip: 0x3227039e2)
jl_call_method_internal at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia_internal.h:210 [inlined]
jl_apply_generic at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/gf.c:1950
jl_apply at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/./julia.h:1392 [inlined]
finish_task at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/task.c:215 [inlined]
start_task at /Users/osx/buildbot/slave/package_osx10_9-x64/build/src/task.c:262

These errors seem to be internal to julia, so I'm submitting them here as a bug. If the bug is in the code, I would expect to throw a regular, non-fatal, exception, not crash. There is a similar bug here (#17003; yuyichao commented "Seems fixed"), but I really can't tell if it's the same thing, there is no "illegal instruction" here.

[JeffBezanson]

In the first example, the StackOverflowError, is there any chance Julia's behavior is correct, i.e. there is actually a stack overflow in ApproxFun?

[ikirill]

@JeffBezanson Oh I see, quite possibly. I'm working on 0.5.1 (the bottom one), so that's the thing I was thinking of when I wrote that.

[yuyichao]

If the stack overflow is expected than the crash would be a dup of #17280 . This is unrelated to #17003

[ikirill]

@yuyichao I can't reproduce the segfault in #17280 with 0.5.1. Also, the problem for me is not the stack overflow itself, but the fatal error in 0.5.1 ("task switch not allowed from inside gc finalizer"). I guess it got fixed between 0.5.1 and 0.6.0-pre.beta.50?

[KristofferC]

Please comment if this still happens.