[petsc-dev] circular dependencies SLEPc

[Jakub Kruzik]

Hello,

as I mentioned in PR #1819, I would like to use SLEPc in PETSc.

Currently when PETSc is configured with --download-slepc, it defines 
PETSC_HAVE_SLEPC and each compilation of PETSc recompiles SLEPc.

The first way to use SLEPc is from an example. That should be easy, all 
we need is to add -lslepc when compiling an example.

The other option is to use SLEPc inside PETSc code. I do not know how to 
achieve this. One way could be to define PETSC_HAVE_SLEPC after the 
compilation of SLEPc and again compile PETSc but this time linking with 
SLEPc. Although, even if it works, it is ugly.

Any ideas on how to achieve the second option?

Cheers,

Jakub