Questions to discuss

[vsoch]

• How frequently to update, and what to update? Currently, the Dockerfile bases that don't require a build matrix are triggered nightly. With the recently added check for changed files, we shouldn't be running all the build matrices. But probably we'd want matrices to be updated if their base image changes? This could be added.

[davidbeckingsale]

I think that we could check weekly - ultimately compiler versions change pretty slowly so we probably don't need to be building very often. Perhaps we could have uptodate understand how to read some kind of schedule with the hierarchy - so some images can be updated more frequently than others?