References ACCESS-NRI/spack-config#81

Background

This file is used by spack >= v1 to index collections of spack-packages within a single repository. We don't use this feature in our instances of spack (having a single spack_repo/access/nri one) but it is required to make the spack repo update command work, which will be used going forward in both build-ci and build-cd.

The PR

• Add spack-repo-index.yaml that points to the spack_repos/access/nri collection of packages

Testing

Tested locally in a docker image using spack-config with branch access-spack-packages-as-git-repo branch (see ACCESS-NRI/spack-config#82):

spack repo list  # Has our ACCESS-NRI/spack-packages repo successfully linked (the [+])
spack repo update access_spack_packages  # And we can update our repository via this command, also with --commit/--tag/--branch flags