[petsc-users] Meaning of PETSc error code 77

[Smith, Barry F.]

   This particular error "Petsc has generated inconsistent data" is a catastrophic error (not, for example, simply failure to solve a system) so it is not possible to by-pass the error. We would need to know exactly where in the PETSc code the error was detected to to help you resolve the problem.

   Barry


> On Feb 8, 2019, at 11:40 AM, aditya kumar via petsc-users <petsc-users at mcs.anl.gov> wrote:
> 
> Hello,
> 
> I am using PETSc with FEniCS project libraries to solve a nonlinear problem. I am using PETSc Krylov solver with the following configuration
> 
> pc = PETScPreconditioner("petsc_amg") 
> PETScOptions.set("mg_levels_ksp_type", "chebyshev")
> PETScOptions.set("mg_levels_pc_type", "jacobi")
> PETScOptions.set("mg_levels_esteig_ksp_type", "cg")
> PETScOptions.set("mg_levels_ksp_chebyshev_esteig_steps", 50)
> solver_u = PETScKrylovSolver("cg", pc)
> 
> 
> 
> I am encountering this error sometimes during the solution of the linear system:
> 
> Error:   Unable to successfully call PETSc function 'KSPSolve'.
> *** Reason:  PETSc error code is: 77 (Petsc has generated inconsistent data).
> *** Where:   This error was encountered inside /tmp/dolfin/dolfin/la/PETScKrylovSolver.cpp. 
> 
> *** Process: 130
> 
> Can anybody help me in understanding the possible reasons for this error code? Or refer me to any available documentation? It will be really helpful. 
> 
> Also, I will like to know if there is a way to prevent the code from stopping due to such PETSc errors, so that I can tweak some parameters to hopefully make it progress.  
> 
> 
> Thanks and Regards,
> Aditya
>