Telcon: 2021 08 11

Spack meeting to be held August 11th, 2021 at 9am PST

Attendees:

Agenda items:

Bootstrapping of binaries (clingo): for the new concretizer we need to install Clingo; we propose to do that automatically by pulling and installing binaries built in our CI (with an option to disable)
Policies for versioning in CI: should we be testing develop versions of packages (i.e. the tip of a branch)?
- Generally we assume not, since bugs in their branch would cause failures in our CI (and our aim is to ensure that stable versions build properly)
The getting-started guide might be too complex
- Proposal to add a set of how-to guides (similar to an FAQ): https://github.com/spack/spack/pull/20018

Workflows

Quincy is using a workflow with:
- multiple upstreams built with different spacks
- Want to assemble a "unified" view from these upstreams in a single container
- has had success containerizing really complicated software envs using spack containerize
Idea is that app devs would:
1. clone spack
2. build spack env that works for application
3. make an upstream for it
4. tell users about this working env by sending the buildcache (or upstream) URL
5. create containers that use software from multiple upstreams/buildcaches
Right now the concretizer won't reuse what's in the buildcache aggressively
- but with #25310 we'll take the hashes/constraints in the upstream into account and reuse them in concretizations
- #25310 will simplify reuse of upstreams and buildcaches.
interesting questions about using upstreams in spack containerize
- Quincy seems to version upstreams in a repo of his own
- in general upstreams won't work in containerize -- you want to use a buildcache (and we'll get better reuse)
  - You can create a buildcache with the upstream packages
  - Greg: you can take an upstream and relocate all packages to the container instance

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