1. --with-lapack-lib was wrong.
2. --with-MPI was wrong; set env vars for MPI wrappers instead.
3. Added version 2.10.1
4. Added shared library variant (True by default). Hypre can build shared or static libraries, but not both in the same build.
Package repositories now look like this:
top-level-dir/
repo.yaml
packages/
libelf/
package.py
mpich/
package.py
...
This leaves room at the top level for additional metadata, source,
per-repo configs, indexes, etc., and it makes it easy to see that
something is a spack repo (just look for repo.yaml and packages).