Upcoming changes on develop

[Todd Gamblin]

Hi all,

As we start to approach the v1.0 Spack release, I want to draw your attention again to our list of upcoming changes due to land on develop:

https://github.com/spack/spack/discussions/30634

We try to keep disruptions on develop to a minimum, but develop *may* be a bit more chaotic than usual as we integrate the bigger changes on that list.

In particular, note that in the next week or so, we are likely to land these two 1.0 features:

1. Some backward-incompatible changes to build caches, for which you’ll need to run a command to migrate your build caches to work with newer Spack. Note that you can have an old (unmigrated) and a new (migrated) build cache present in the same place;  and
2. Compiler dependencies, which will move default compiler detection to packages.yaml and change some spec indexing semantics.

(2) is the biggest of these changes but (1) may be more disruptive.

We recommend trying out the latest 1.0 alpha releases soon, to ensure that we catch any issues with your workflow, especially if you are the author or maintainer of a compiler package in Spack:

https://github.com/spack/spack/releases/tag/v1.0.0-alpha.4

We’re really looking forward to the release in June, so bear with us as we start getting these features merged. If you absolutely need stability right now, we recommend sticking with the latest v0.23 patch release (currently v0.23.1) instead of staying on bleeding-edge of develop.

As always, let us know if you have issues.

Thanks,

-Todd and the Spack team