[petsc-users] erratic bug with nested PETSc and SLEPc

[Jose E. Roman]

> El 25 ene 2016, a las 11:34, Marco Zocca <zocca.marco at gmail.com> escribió:
> 
> Dear all,
> 
> I have a simple code with a matrix filling, assembly and output to stdout.
> This in turn is wrapped within a SLEPc bracket, and that in turn in a
> PETSc bracket, both called with default options
> (`XInitializeNoArguments`).
> 
> I run this on my laptop, MPI comm size == 1.
> 
> Issue: _sometimes_ the above crashes upon exit from the SLEPc bracket
> (i.e. after printing out the matrix), with an error code > 8000 . I
> haven't found this documented anywhere.
> It's funny because this doesn't happen with probability 1 and no
> conditions change (running from a makefile).
> 
> Other times it simply works.
> 
> In general, when using both PETSc and SLEPc functionality, is it
> enough to link to SLEPc alone? Does it take care of importing all of
> PETSc?
> 
> Any hints re. this behaviour?
> 
> 
> Thank you in advance and kind regards,
> 
> Marco

SLEPc makefiles include PETSc makefiles. Generally you just need to include ${SLEPC_DIR}/lib/slepc/conf/slepc_common and then add e.g. ${SLEPC_EPS_LIB} in your link line, which in turn  will add ${PETSC_KSP_LIB}. [Note: if you need other components of PETSc such as SNES or TS you may need to add these, but it is usually not necessary unless PETSc has been configured --with-single-library=0].

If you call both SlepcInitialize() and PetscInitialize(), in any order, it should work. It should work also with the NoArguments versions. So I don't know where the problem is. If you share a test code I could try to reproduce the problem.

Jose