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<p class="MsoNormal"><span style="font-size:11.0pt">Dear all,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">For the same code and same input file, using '-pc_factor_nonzeros_along_diagonal' causing a seg fault, while '-pc_factor_shift_type nonzero -pc_factor_shift_amount 1e-8' works fine.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">The seg fault happened after the very first residual vec norm was evaluated, somewhere before stepping into the second residual vec norm evaluation, i.e.,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="p1"><span class="apple-converted-space"> </span><span class="s1">NL Step =</span><span class="apple-converted-space">
</span><span class="s1">0, fnorm =</span><span class="apple-converted-space"> </span>
<span class="s1">5.22084E+01</span><o:p></o:p></p>
<p class="p1"><span class="s1">Segmentation fault: 11</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">I tend to believe that it is not in my `snesFormFunction` because I used print to make sure to see that the ‘sef fault’ is after snesFormFunction was called in the first residual vec norm was shown, and before
snesFormFunction was called for the next residual vec norm.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">I am behind ‘moose,’ so the debug version did not tell much info, showing the exact error message.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">It’s not an urgent issue for me, since the other option worked fine.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Best,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">-Ling<o:p></o:p></span></p>
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