Update petsc version installing_with_spack.md

[nedpfeiffer]

Merge request type

• New feature
• Resolves bug
• Documentation
• Other

Relates to

• OPFLOW
• SOPFLOW
• SCOPFLOW
• TCOPFLOW
• CMake build system
• Spack configuration
• Manual
• Web docs
• Other

This MR updates

• Header files
• Source code
• CMake build system
• Spack configuration
• Web docs
• Manual
• Other

Summary

It appears the Spack installation instructions are outdated. I received the following error:

ubuntu@workstation:~$ spack install exago@develop%gcc \
  ^openmpi ^[email protected]+coinhsl~mumps ^coinhsl+blas \
  ^[email protected]+mpi~hypre~superlu-dist~mumps+shared
==> Error: concretization failed for the following reasons:

   1. Cannot select a single "version" for package "petsc"
   2. Cannot satisfy 'petsc@:3.13'
   3. Cannot satisfy '[email protected]'
   4. Cannot satisfy '[email protected]:'
   5. Cannot satisfy '[email protected]:'
   6. Cannot satisfy '[email protected]:3.14'
   7. Cannot satisfy '[email protected]'
   8. Cannot satisfy '[email protected]:3.13'
   9. Cannot satisfy '[email protected]:'
        required because exago depends on [email protected]: when @1.6: 
          required because exago@develop%gcc ^coinhsl+blas ^[email protected]+coinhsl~mumps ^openmpi ^[email protected]~hypre+mpi~mumps+shared~superlu-dist requested explicitly 
   10. Cannot satisfy '[email protected]'
        required because exago@develop%gcc ^coinhsl+blas ^[email protected]+coinhsl~mumps ^openmpi ^[email protected]~hypre+mpi~mumps+shared~superlu-dist requested explicitly 
   11. Cannot satisfy '[email protected]:' and '[email protected]
        required because exago depends on [email protected]: when @1.6: 
          required because exago@develop%gcc ^coinhsl+blas ^[email protected]+coinhsl~mumps ^openmpi ^[email protected]~hypre+mpi~mumps+shared~superlu-dist requested explicitly 
        required because exago@develop%gcc ^coinhsl+blas ^[email protected]+coinhsl~mumps ^openmpi ^[email protected]~hypre+mpi~mumps+shared~superlu-dist requested explicitly 
   12. Cannot satisfy '[email protected]' and '[email protected]:
        required because exago depends on [email protected]: when @1.6: 
          required because exago@develop%gcc ^coinhsl+blas ^[email protected]+coinhsl~mumps ^openmpi ^[email protected]~hypre+mpi~mumps+shared~superlu-dist requested explicitly 
        required because exago@develop%gcc ^coinhsl+blas ^[email protected]+coinhsl~mumps ^openmpi ^[email protected]~hypre+mpi~mumps+shared~superlu-dist requested explicitly

Specifying petsc version 3.19 as the required version allowed me to continue installation.

[abhyshr]

@cameronrutherford @jaelynlitz : Can you take a look at this PR when you get a chance.

[cameronrutherford]

LGTM - we have spack version constraints in ExaGO's package.py that capture this, but our documentation lacks here and struggles to keep up to date. Perhaps we should remove the PETSc version spec from these docs altogether?

[cameronrutherford]

I'll wait for @jaelynlitz to get back from vacation to give a second opinion, but thanks for this @nedpfeiffer!! Great catch

[jaelynlitz]

LGTM - I agree with @cameronrutherford that we could probably remove the version from the docs and let the spack package handle the version, one less thing to remember to update. FYI @nedpfeiffer we are compatible with petsc 3.20 as well if you want to upgrade 😄