[petsc-users] error message

[Sam Guo]

Barry,
     Thanks.

Sam

On Tuesday, March 16, 2021, Barry Smith <bsmith at petsc.dev> wrote:

>
>  Sam,
>
>    You can pass a simple C function to PetscPushErrorHandler() that prints
> the top message and then immediately aborts to get the effect you want. But
> I agree with Dave you lose a lot of useful information by producing such a
> simple error message.
>
>   Barry
>
> On Mar 16, 2021, at 5:43 PM, Dave May <dave.mayhem23 at gmail.com> wrote:
>
>
>
> On Tue, 16 Mar 2021 at 19:50, Sam Guo <sam.guo at cd-adapco.com> wrote:
>
>> Dear PETSc dev team,
>>    When there is an PETSc error, I go following overly verbose error
>> message. Is it possible to get a simple error message like "Initial vector
>> is zero or belongs to the deflection space"?
>>
>>
> When an error occurs and the execution is halted, a verbose and
> informative error message is shown.
> I would argue this is useful (very useful), and should never ever be
> shortened or truncated.
>
> This error thrown by PETSc gives you a stack trace. You can see where the
> error occurred, and the calling code which resulted in the error. In
> anything but a trivial code, this information is incredibly useful to
> isolate and fix the problem. I also think it's neat that you see the stack
> without having to even use a debugger.
>
> Currently if your code does not produce errors, no message is displayed.
> However, when an error occurs, a loud, long and informative message is
> displayed - and the code stops.
> What is the use case which would cause / require you to change the current
> behaviour?
>
> Thanks,
> Dave
>
>
>
>> Thanks,
>> Sam
>>
>> [0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------
>> [0]PETSC ERROR: Initial vector is zero or belongs to the deflation space
>> [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.
>> [0]PETSC ERROR: Petsc Release Version 3.11.3, Jun, 26, 2019
>> [0]PETSC ERROR: Unknown Name on a arch-starccmplus_serial_real named pl2denbg0033pc.net.plm.eds.com by cd3ppw Tue Mar 16 16:19:28 2021
>> [0]PETSC ERROR: Configure options --with-x=0 --with-fc=0 --with-debugging=0 --with-blaslapack-dir=/usr/local/jenkins/dev1/mkl/2017.2-cda-001/linux/lib/intel64/../.. --with-mpi=0 -CFLAGS=-O3 -CXXFLAGS=-O3 --with-clean=1 --force --with-scalar-type=real
>> [0]PETSC ERROR: #1 <https://stash.cd-adapco.com/projects/UPS/repos/star/pull-requests/1> EPSGetStartVector() line 806 in ../../../slepc/src/eps/interface/epssolve.c
>> [0]PETSC ERROR: #2 <https://stash.cd-adapco.com/projects/UPS/repos/star/pull-requests/2> EPSSolve_KrylovSchur_Default() line 259 in ../../../slepc/src/eps/impls/krylov/krylovschur/krylovschur.c
>> [0]PETSC ERROR: #3 <https://stash.cd-adapco.com/projects/UPS/repos/star/pull-requests/3> EPSSolve() line 149 in ../../../slepc/src/eps/interface/epssolve.c
>>
>>
>
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