<div dir="ltr"><div dir="ltr">Trying it slightly differently, I do see it's a SIGFPE, arithmetic exception but all it shows is that it's an error in TSSolve but no further than that. <br><br>[sajid@xrm free_space]$ gdb ex_modify <br>GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-100.el7<br>Copyright (C) 2013 Free Software Foundation, Inc.<br>License GPLv3+: GNU GPL version 3 or later <<a href="http://gnu.org/licenses/gpl.html">http://gnu.org/licenses/gpl.html</a>><br>This is free software: you are free to change and redistribute it.<br>There is NO WARRANTY, to the extent permitted by law.  Type "show copying"<br>and "show warranty" for details.<br>This GDB was configured as "x86_64-redhat-linux-gnu".<br>For bug reporting instructions, please see:<br><<a href="http://www.gnu.org/software/gdb/bugs/">http://www.gnu.org/software/gdb/bugs/</a>>...<br>Reading symbols from /raid/home/sajid/packages/xwp_petsc/2d/free_space/ex_modify...done.<br>(gdb) run -ts_type cn --args -fp_trap<br>Starting program: /raid/home/sajid/packages/xwp_petsc/2d/free_space/ex_modify -ts_type cn --args -fp_trap<br>[Thread debugging using libthread_db enabled]<br>Using host libthread_db library "/lib64/libthread_db.so.1".<br>warning: File "/raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-4.8.5/gcc-7.3.0-qrjpi76aeo4bysagruwwfii6oneh56lj/lib64/libstdc++.<a href="http://so.6.0.24-gdb.py">so.6.0.24-gdb.py</a>" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load:/usr/bin/mono-gdb.py".<br>To enable execution of this file add<br>        add-auto-load-safe-path /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-4.8.5/gcc-7.3.0-qrjpi76aeo4bysagruwwfii6oneh56lj/lib64/libstdc++.<a href="http://so.6.0.24-gdb.py">so.6.0.24-gdb.py</a><br>line to your configuration file "/raid/home/sajid/.gdbinit".<br>To completely disable this security protection add<br>        set auto-load safe-path /<br>line to your configuration file "/raid/home/sajid/.gdbinit".<br>For more information about this security protection see the<br>"Auto-loading safe path" section in the GDB manual.  E.g., run from the shell:<br>        info "(gdb)Auto-loading safe path"<br>Solving a linear TS problem on 1 processor<br>mx : 512, my: 512 lambda : 1.239840e-10<br><br>Program received signal SIGFPE, Arithmetic exception.<br>__muldc3 (a=-6.6364040265716871e-306, b=1.1689456061105587e-305, c=-0.0024992568840190117, d=0.024886737403015963)<br>    at /raid/home/sajid/packages/spack/var/spack/stage/gcc-7.3.0-qrjpi76aeo4bysagruwwfii6oneh56lj/gcc-7.3.0/libgcc/libgcc2.c:1978<br>1978    /raid/home/sajid/packages/spack/var/spack/stage/gcc-7.3.0-qrjpi76aeo4bysagruwwfii6oneh56lj/gcc-7.3.0/libgcc/libgcc2.c: No such file or directory.<br>Missing separate debuginfos, use: debuginfo-install blas-3.4.2-8.el7.x86_64 bzip2-libs-1.0.6-13.el7.x86_64 elfutils-libelf-0.168-8.el7.x86_64 elfutils-libs-0.168-8.el7.x86_64 glibc-2.17-196.el7.x86_64 lapack-3.4.2-8.el7.x86_64 libattr-2.4.46-12.el7.x86_64 libcap-2.22-9.el7.x86_64 libgfortran-4.8.5-16.el7.x86_64 libxml2-2.9.1-6.el7_2.3.x86_64 systemd-libs-219-42.el7_4.4.x86_64 xz-libs-5.2.2-1.el7.x86_64 zlib-1.2.7-17.el7.x86_64<br>(gdb) bt<br>#0  __muldc3 (a=-6.6364040265716871e-306, b=1.1689456061105587e-305, c=-0.0024992568840190117, d=0.024886737403015963)<br>    at /raid/home/sajid/packages/spack/var/spack/stage/gcc-7.3.0-qrjpi76aeo4bysagruwwfii6oneh56lj/gcc-7.3.0/libgcc/libgcc2.c:1978<br>#1  0x00007ffff630fe87 in MatSolve_SeqAIJ_NaturalOrdering ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#2  0x00007ffff5ba61a8 in MatSolve ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#3  0x00007ffff6bc8a55 in PCApply_ILU ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#4  0x00007ffff6cde6eb in PCApply ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#5  0x00007ffff6e3ad4a in KSP_PCApply ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#6  0x00007ffff6e3bc36 in KSPInitialResidual ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#7  0x00007ffff6dc0736 in KSPSolve_GMRES ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#8  0x00007ffff6e1158e in KSPSolve ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#9  0x00007ffff6fac311 in SNESSolve_KSPONLY ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#10 0x00007ffff6f346c7 in SNESSolve ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#11 0x00007ffff714d58b in TSTheta_SNESSolve ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#12 0x00007ffff714df63 in TSStep_Theta ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#13 0x00007ffff7053ebe in TSStep ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>---Type <return> to continue, or q <return> to quit---<br>#14 0x00007ffff70560bc in TSSolve ()<br>   from /raid/home/sajid/packages/spack/opt/spack/linux-rhel7-x86_64/gcc-7.3.0/petsc-develop-2u6vuwagkoczyvnpsubzrubmtmpfhhkj/lib/libpetsc.so.3.010<br>#15 0x000000000040271d in main (argc=5, argv=0x7fffffffce38) at /raid/home/sajid/packages/xwp_petsc/2d/free_space/ex_modify.c:183<br><br></div></div>