This avoids using a system-installed CUDA package. In the future a
variant can be added to allow using Spack-installed CUDA, but for
now CUDA support is always disabled.

Added a variant to allow conduit to build with newer versions of
HDF5.  Set the default for the variant to prefer compatibility mode
with HDF5 v1.8

- disable sundials varaiant for dealii and mfem - as they are incomatible with sundials@4.1.0

- add a patch to fix build error with superlu-dist

* Added a package for chapel.

* flake8 compliance.

* serialize the F90 interface build

* serialize the F90 interface build

* netgen: update broken URL

* netgen: fix url_for_version URL

openfoam-com needs flex's FlexLexer.h, which can only be found if flex
is also a link dependency.

Patch extracted from #7536 courtesy of @mgsternberg

* update R to v3.5.3

* abinit: Fix building with hdf5/netcdf.

* gromacs: Fix attempt to build with cuda support when 'cuda=False'

If for some reason there's a cuda toolkit installed by other means,
(i.e. not by spack) cmake will still try to build with cuda support,
even though 'cuda=False' is the default of the spec.

* Revert "abinit: Fix building with hdf5/netcdf."

This reverts commit e16f725e37b91193fe519b1821446c76ab551928.

This should not be here.

* Branson: provide new versions.

+ Also update dependencies (newer version have fewer dependencies).

* fix style issue