Function only causes segfaults inside package...?

[Chris Rackauckas]

I was implementing a bunch of Runge-Kutta tableaus and ran into an issue. Specific tableaus which are defined inside of a function inside of DifferentialEquations.jl cause segfaults, but those exact same functions will not segfault when not inside the package. For example, the code (on master):

using DifferentialEquations
constructVern6()

causes segfaults (the Windows and Linux versions at the bottom of the post) (tested on v0.5 and v0.6). However, I can take that same function:

function constructVern6(T::Type = Float64)

  c1   =T(3//50)

  c2   =T(1439//15000)

  c3   =T(1439//10000)

  c4   =T(4973//10000)

  c5   =T(389//400)

  c6   =T(1999//2000)

  a21  =T(3//50)

  a31  =T(519479//27000000)

  a32  =T(2070721//27000000)

  a41  =T(1439//40000)

  a43  =T(4317//40000)

  a51  =T(109225017611//82828840000)

  a53  =T(-417627820623//82828840000)

  a54  =T(43699198143//10353605000)

  a61  =T(-8036815292643907349452552172369//191934985946683241245914401600)

  a63  =T(246134619571490020064824665//1543816496655405117602368)

  a64  =T(-13880495956885686234074067279//113663489566254201783474344)

  a65  =T(755005057777788994734129//136485922925633667082436)

  a71  =T(-1663299841566102097180506666498880934230261//30558424506156170307020957791311384232000)

  a73  =T(130838124195285491799043628811093033//631862949514135618861563657970240)

  a74  =T(-3287100453856023634160618787153901962873//20724314915376755629135711026851409200)

  a75  =T(2771826790140332140865242520369241//396438716042723436917079980147600)

  a76  =T(-1799166916139193//96743806114007800)

  a81  =T(-832144750039369683895428386437986853923637763//15222974550069600748763651844667619945204887)

  a83  =T(818622075710363565982285196611368750//3936576237903728151856072395343129)

  a84  =T(-9818985165491658464841194581385463434793741875//61642597962658994069869370923196463581866011)

  a85  =T(31796692141848558720425711042548134769375//4530254033500045975557858016006308628092)

  a86  =T(-14064542118843830075//766928748264306853644)

  a87  =T(-1424670304836288125//2782839104764768088217)

  a91  =T(382735282417//11129397249634)

  a94  =T(5535620703125000//21434089949505429)

  a95  =T(13867056347656250//32943296570459319)

  a96  =T(626271188750//142160006043)

  a97  =T(-51160788125000//289890548217)

  a98  =T(163193540017//946795234)

  b1   =T(124310637869885675646798613//2890072468789466426596827670)

  b4   =T(265863151737164990361330921875//1113197271463372303940319369579)

  b5   =T(3075493557174030806536302953125//6843749922042323876546949699876)

  b6   =T(67798000008733879813263055//29532792147666737550036372)

  b7   =T(-1099436585155390846238326375//15055706496446408859196167)

  b8   =T(26171252653086373181571802//368794478890732346033505)

  b9   =T(1//30)

  return c1,c2,c3,c4,c5,c6,a21,a31,a32,a41,a43,a51,a53,a54,a61,a63,a64,a65,a71,a73,a74,a75,a76,a81,a83,a84,a85,a86,a87,a91,a94,a95,a96,a97,a98,b1,b4,b5,b6,b7,b8,b9

end

put it in a script, run it, and call the function without segfaulting. I can even put that in a module without segfaulting!

I have been able to pin down the issue to be due to methods which look like this and include items that would be parsed as Rational{BigInt}. Any tableaus which are parsed to BigFloats or Rational{Int} don't have this issue. So it has something to do with the giant rationals (I have a few more examples if needed). @Ismael-VC noted that when he deleted his lib and v0.6 folders and re-installed, the error went away for him (that did not work for me). Thus I am thinking it may have to do with precompilation? Note that my precompiling hinting file does not hint these functions since they are brand new.

I will likely file an issue on the julialang issue if I can pinpoint the example to something which doesn't require installing DifferentialEquations.jl (because it is a large package). However, as I previously noted, I cannot re-create this outside of the package for some reason! Any help would be great!

P.S. For those that are curious, DifferentialEquations.jl does contain over 100 ODE solver algorithms now, with each having convergence tests (except for the handful with this segfault problem)!

-------------------------------------------------------------------------

Linux Segfault Message:

signal (11): Segmentation fault

while loading console, in expression starting on line 1

gcd at ./gmp.jl:256 [inlined]

Type at ./rational.jl:9

constructVern6 at /home/crackauc/.julia/v0.5/DifferentialEquations/src/ode/ode_tableaus.jl:1604

constructVern6 at /home/crackauc/.julia/v0.5/DifferentialEquations/src/ode/ode_tableaus.jl:1586

#99 at /home/crackauc/.julia/v0.5/Atom/src/eval.jl:39

withpath at /home/crackauc/.julia/v0.5/Requires/src/require.jl:37

withpath at /home/crackauc/.julia/v0.5/Atom/src/eval.jl:45

macro expansion at /home/crackauc/.julia/v0.5/Atom/src/eval.jl:107 [inlined]

#98 at ./task.jl:54

unknown function (ip: 0xffffffffffffffff)

Allocations: 36331487 (Pool: 36324167; Big: 7320); GC: 38

Windows Segfault Message:

Please submit a bug report with steps to reproduce this fault, and any error messages that follow (in their entirety). Thanks.

Exception: EXCEPTION_ACCESS_VIOLATION at 0xcbd6e8 -- while loading console, in expression starting on line 1

gcd at .\gmp.jl:256 [inlined]

Type at .\rational.jl:9

constructVern6 at C:\Users\Chris\.julia\v0.6\DifferentialEquations\src\ode\ode_tableaus.jl:1604

constructVern6 at C:\Users\Chris\.julia\v0.6\DifferentialEquations\src\ode\ode_tableaus.jl:1586

jl_call_method_internal at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\julia_internal.h:192 [inlined]

jl_apply_generic at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\gf.c:1930

do_call at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\interpreter.c:66

eval at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\interpreter.c:190

jl_toplevel_eval_flex at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\toplevel.c:558

jl_parse_eval_all at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\ast.c:717

include_string at .\loading.jl:380

jl_call_method_internal at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\julia_internal.h:192 [inlined]

jl_apply_generic at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\gf.c:1930

do_call at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\interpreter.c:66

eval at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\interpreter.c:190

eval_body at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\interpreter.c:469

jl_interpret_call at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\interpreter.c:573

jl_toplevel_eval_flex at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\toplevel.c:572 [inlined]

jl_toplevel_eval at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\toplevel.c:580

jl_toplevel_eval_in_warn at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\builtins.c:576

eval at .\boot.jl:234

jl_call_method_internal at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\julia_internal.h:192 [inlined]

jl_apply_generic at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\gf.c:1930

#99 at C:\Users\Chris\.julia\v0.6\Atom\src\eval.jl:39

withpath at C:\Users\Chris\.julia\v0.6\Requires\src\require.jl:37

jl_call_method_internal at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\julia_internal.h:192 [inlined]

jl_apply_generic at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\gf.c:1930

withpath at C:\Users\Chris\.julia\v0.6\Atom\src\eval.jl:45

macro expansion at C:\Users\Chris\.julia\v0.6\Atom\src\eval.jl:107 [inlined]

#98 at .\task.jl:54

jl_call_method_internal at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\julia_internal.h:192 [inlined]

jl_apply_generic at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\gf.c:1930

jl_apply at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\julia.h:1392 [inlined]

start_task at /home/Administrator/buildbot/slave/package_win6_2-x64/build/src/home/Administrator/buildbot/slave/package_win6_2-x64/build/src\task.c:253

Allocations: 40695853 (Pool: 40684045; Big: 11808); GC: 53

[Chris Rackauckas]

Hello everyone,

  I narrowed down the issue to a small example. Check out this repo which causes the segfault in just a few lines. An issue for it has been posted on JuliaLang.