Rebase onto spack v0.23.0

[xylar]

Spack 0.23.0 has been released:
https://github.com/spack/spack/releases/tag/v0.23.0

I have a branch where I did the rebase as best I could:
https://github.com/xylar/spack/tree/rebase-onto-0.23.0
It was messier than usual, in large part because they have added new dependencies on languages like:

depends_on("cxx", type="build") 

This means that the results could be messy and require some fixes.

[xylar]

@ikalash, when would be a good time to force-push my rebase branch to develop and see how things go? Would this week be better than next?

[ikalash]

@xylar : yesterday Trilinos in the spack build got broken b/c of some changes to the syntax for specifying a Kokkos option. I just fixed it. Can we wait till the nightly spack build is clean again? Hopefully it will be tonight. I will ping you when it is.

[xylar]

Yep, sounds fine. Keep me posted. I'll cherry-pick your latest commits onto my rebased branch so nothing gets lost.

[ikalash]

I haven't forgotten about this. The nightly spack build is still down due to an omega-h + Kokkos issue (sandialabs/Albany#1092 (comment)). I'll let you know when it's resolved. Hopefully next weke.

[xylar]

Thanks for the update. No rush.

[ikalash]

It's OK to merge now.

[xylar]

Great, think you for letting me know. I'll double check that nothing has changed and force-push now.

[xylar]

Done!