Segmentation fault when running SNOPT7 on a large problem

[Delyle Polet]

I am using SNOP7 on MATLAB through GPOPS-II (v. 2.1) on a large optimization problem. Sometimes, when running this program, MATLAB crashes due to a segmentation fault.

Is there an obvious cause for this error? Any suggestions for fixing it?

I am running MATLAB 2015b on a Macintosh 64-bit laptop (OS 10.10.5) with 16 GB 1600 MHz DDR3 ram and a 2.8 GHz Intel Core i7 processor.


The final terminal output before the crash is:

…
Itn 44237: LU rook pivoting tols 1.01 1.01
Itn 44237: Large QP reduced gradient
Itn 44237: Hessian reset

Minor NonOpt QP mult QP step rgNorm Elastic QP obj nS
1500 267 -1.1E+01 6.4E-13 1.5128432E-01
Itn 44286: BR factorize
1600 86 -3.6E-01 8.6E-09 1.5202504E-01


And the terminal output after the crash is:

------------------------------------------------------------------------
Segmentation violation detected at Wed Feb 24 09:30:06 2016
------------------------------------------------------------------------

Configuration:
Crash Decoding : Disabled
Crash Mode : continue (default)
Current Graphics Driver: Unknown hardware
Current Visual : Quartz
Default Encoding : ISO-8859-1
Host Name : uws084053usr.uws.ualberta.ca
MATLAB Architecture : maci64
MATLAB Root : /Applications/MATLAB_R2015b.app
MATLAB Version : 8.6.0.267246 (R2015b)
OpenGL : hardware
Operating System : Darwin 14.5.0 Darwin Kernel Version 14.5.0: Tue Sep 1 21:23:09 PDT 2015; root:xnu-2782.50.1~1/RELEASE_X86_64 x86_64
Processor ID : x86 Family 6 Model 70 Stepping 1, GenuineIntel
Virtual Machine : Java 1.7.0_75-b13 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode
Window System : Quartz

Fault Count: 1


Abnormal termination:
Segmentation violation

Register State (from fault):
…{some output suppressed because I don't think it's relevant}...

[ 7] 0x000000012bb5f1fc <unknown-module>+00000000
[ 8] 0x00000001282dfb3d /Users/delyle/Documents/MATLAB/snopt7/matlab/snoptmex.mexmaci64+00142141 lu6sol_+00000732
[ 9] 0x00000001282d91b8 /Users/delyle/Documents/MATLAB/snopt7/matlab/snoptmex.mexmaci64+00115128 s2bsol_+00000915
[ 10] 0x00000001282ff83f /Users/delyle/Documents/MATLAB/snopt7/matlab/snoptmex.mexmaci64+00272447 s5setpi_+00000115
[ 11] 0x000000012830a1d5 /Users/delyle/Documents/MATLAB/snopt7/matlab/snoptmex.mexmaci64+00315861 s5qp_+00005711
[ 12] 0x000000012832a005 /Users/delyle/Documents/MATLAB/snopt7/matlab/snoptmex.mexmaci64+00446469 s8solveqp_+00006271
[ 13] 0x0000000128332ec1 /Users/delyle/Documents/MATLAB/snopt7/matlab/snoptmex.mexmaci64+00483009 s8sqp_+00006007
[ 14] 0x000000012833aab4 /Users/delyle/Documents/MATLAB/snopt7/matlab/snoptmex.mexmaci64+00514740 s8solve_+00010211
[ 15] 0x00000001282c564a /Users/delyle/Documents/MATLAB/snopt7/matlab/snoptmex.mexmaci64+00034378 snkera_+00006868
[ 16] 0x00000001282c5b4c /Users/delyle/Documents/MATLAB/snopt7/matlab/snoptmex.mexmaci64+00035660 snopta_+00000690
[ 17] 0x00000001282c20d0 /Users/delyle/Documents/MATLAB/snopt7/matlab/snoptmex.mexmaci64+00020688 snmxsolve_+00006957
[ 18] 0x00000001282c2e8b /Users/delyle/Documents/MATLAB/snopt7/matlab/snoptmex.mexmaci64+00024203 mexfunction_+00001789
…{remaining output suppressed because I don't think it's relevant}...

[Delyle Polet]

After observing some more segmentation faults, it seems to always occur shortly after "LU rook     pivoting tols" is displayed in the terminal.

[Elizabeth Wong]

Hi Delyle,

This may be related to a bug in lusol (the linear solver inside SNOPT) that we recently fixed.  Are you using a trial version or full version of SNOPT?  If it's the trial, I'd download the latest version, which has the bug fix.  If you have the full version, please email me at elw...@ucsd.edu.

--Elizabeth