LinearOperator unit test fails on precise-i386

[Johannes Ring]

The LinearOperator unit test (test/unit/la/python/LinearOperator.py) fails to run on the precise-i386 buildbot (32-bit). The test hangs and the buildbot time out. When running the test manually, I get the following error message:

$ mpirun -np 3 python LinearOperator.py
Process 0: Number of global vertices: 81
Process 0: Number of global cells: 128
Process 0: *** Warning: UnitSquare is deprecated. Use UnitSquareMesh.
Process 1: *** Warning: UnitSquare is deprecated. Use UnitSquareMesh.
Process 2: *** Warning: UnitSquare is deprecated. Use UnitSquareMesh.

Testing DOLFIN la/LinearOperator (matrix-free) interface
--------------------------------------------------------

Testing DOLFIN la/LinearOperator (matrix-free) interface
--------------------------------------------------------

Testing DOLFIN la/LinearOperator (matrix-free) interface
--------------------------------------------------------
Process 0: Number of global vertices: 81
Process 0: Number of global cells: 128
Process 0: *** Warning: UnitSquare is deprecated. Use UnitSquareMesh.
Process 2: *** Warning: UnitSquare is deprecated. Use UnitSquareMesh.
Process 1: *** Warning: UnitSquare is deprecated. Use UnitSquareMesh.
Process 0: Solving linear system of size 81 x 81 (PETSc Krylov solver).
[1]PETSC ERROR: --------------------- Error Message ------------------------------------
[1]PETSC ERROR: Arguments are incompatible!
[1]PETSC ERROR: Incompatible vector local lengths 27 != 30!
[1]PETSC ERROR: ------------------------------------------------------------------------
[1]PETSC ERROR: Petsc Release Version 3.3.0, Patch 3, Wed Aug 29 11:26:24 CDT 2012
[1]PETSC ERROR: See docs/changes/index.html for recent updates.
[1]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
[1]PETSC ERROR: See docs/index.html for manual pages.
[1]PETSC ERROR: ------------------------------------------------------------------------
[1]PETSC ERROR: Unknown Name on a linux-gnu named prceise32-bbot by buildbot Thu Nov 29 13:08:41 2012
[1]PETSC ERROR: Libraries linked from /home/buildbot/local/lib
[1]PETSC ERROR: Configure run at Thu Nov 29 08:32:50 2012
[1]PETSC ERROR: Configure options COPTFLAGS=-O2 --with-debugging=0 --with-shared-libraries=1 --with-clanguage=cxx --with-c-support=1 --download-umfpack=1 --download-hypre=1 --download-mumps=1 --download-scalapack=1 --download-blacs=1 --download-ptscotch=1 --download-scotch=1 --download-metis=1 --download-parmetis=1 --with-ml=1 --with-ml-lib=/home/buildbot/local/lib/libml.so --with-ml-include=/home/buildbot/local/include/trilinos --prefix=/home/buildbot/local
[1]PETSC ERROR: ------------------------------------------------------------------------
[1]PETSC ERROR: VecCopy() line 1742 in /home/buildbot/local/src/petsc-3.3-p3/src/vec/vec/interface/vector.c
[1]PETSC ERROR: KSPInitialResidual() line 60 in /home/buildbot/local/src/petsc-3.3-p3/src/ksp/ksp/interface/itres.c
[1]PETSC ERROR: KSPSolve_GMRES() line 230 in /home/buildbot/local/src/petsc-3.3-p3/src/ksp/ksp/impls/gmres/gmres.c
[1]PETSC ERROR: KSPSolve() line 446 in /home/buildbot/local/src/petsc-3.3-p3/src/ksp/ksp/interface/itfunc.c
[0]PETSC ERROR: --------------------- Error Message ------------------------------------
[0]PETSC ERROR: Arguments are incompatible!
[0]PETSC ERROR: Incompatible vector local lengths 27 != 24!
[0]PETSC ERROR: ------------------------------------------------------------------------
[0]PETSC ERROR: Petsc Release Version 3.3.0, Patch 3, Wed Aug 29 11:26:24 CDT 2012
[0]PETSC ERROR: See docs/changes/index.html for recent updates.
[0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
[0]PETSC ERROR: See docs/index.html for manual pages.
[0]PETSC ERROR: ------------------------------------------------------------------------
[0]PETSC ERROR: Unknown Name on a linux-gnu named prceise32-bbot by buildbot Thu Nov 29 13:08:41 2012
[0]PETSC ERROR: Libraries linked from /home/buildbot/local/lib
[0]PETSC ERROR: Configure run at Thu Nov 29 08:32:50 2012
[0]PETSC ERROR: Configure options COPTFLAGS=-O2 --with-debugging=0 --with-shared-libraries=1 --with-clanguage=cxx --with-c-support=1 --download-umfpack=1 --download-hypre=1 --download-mumps=1 --download-scalapack=1 --download-blacs=1 --download-ptscotch=1 --download-scotch=1 --download-metis=1 --download-parmetis=1 --with-ml=1 --with-ml-lib=/home/buildbot/local/lib/libml.so --with-ml-include=/home/buildbot/local/include/trilinos --prefix=/home/buildbot/local
[0]PETSC ERROR: ------------------------------------------------------------------------
[0]PETSC ERROR: VecCopy() line 1742 in /home/buildbot/local/src/petsc-3.3-p3/src/vec/vec/interface/vector.c
[0]PETSC ERROR: KSPInitialResidual() line 60 in /home/buildbot/local/src/petsc-3.3-p3/src/ksp/ksp/interface/itres.c
[0]PETSC ERROR: KSPSolve_GMRES() line 230 in /home/buildbot/local/src/petsc-3.3-p3/src/ksp/ksp/impls/gmres/gmres.c
[0]PETSC ERROR: KSPSolve() line 446 in /home/buildbot/local/src/petsc-3.3-p3/src/ksp/ksp/interface/itfunc.c
^Cmpirun: killing job...

[Johannes Ring (johannr)]

This is the error I get when using the uBLAS backend instead of PETSc:

ERROR: test_linear_operator (__main__.TestLinearOperator)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "LinearOperator.py", line 76, in test_linear_operator
    solve(A, x, b, "gmres", "none")
  File "/home/buildbot/fenicsbbot/trunk/dolfin-full/lib/python2.7/site-packages/dolfin/fem/solving.py", line 278, in solve
    return cpp.la_solve(*args)
  File "/home/buildbot/fenicsbbot/trunk/dolfin-full/lib/python2.7/site-packages/dolfin/cpp/la.py", line 4195, in la_solve
    return _la.la_solve(*args)
RuntimeError:

*** -------------------------------------------------------------------------
*** DOLFIN encountered an error. If you are not able to resolve this issue
*** using the information listed below, you can ask for help at
***
*** https://answers.launchpad.net/dolfin
***
*** Remember to include the error message listed below and, if possible,
*** include a *minimal* running example to reproduce the error.
***
*** -------------------------------------------------------------------------
*** Error: Unable to solve linear system using uBLAS Krylov solver.
*** Reason: Solution failed to converge.
*** Where: This error was encountered inside uBLASKrylovSolver.h.
*** Process: 0

[Johannes Ring (johannr)]

The same failure happens now on squeeze-amd64. This bulidbot is using the Debian OpenMPI package (version 1.4.2) , while the precise-i386 buildbot is using OpenMPI 1.6.2 (built using Dorsal). Both of them are using PETSc 3.3-p3. I'm wondering if this is related to lp:1036992.