With a PETSc -prefix install after the install is complete one can run from the PETSc build directory the entire test suite with
PETSC_DIR=/prefix_install_location make alltests
this uses mpiexec and can take a while to run. Note you do NOT want this run automatically with
spack install petsc

After a
spack install petsc
I would like to be able to initiate the same test suite. But I don't even know where the build directory is. So do you plan to provide something like
spack alltests(use whatever name you want here) petsc
where I would provide a function in the petsc/package.py that would be called to run the big test suite? This would be useful. All I would need available in the function I write is the petsc prefix directory and the petsc build directory.