Working with Multiple Repositories#

The repositories covered by these working practices all interact with and have dependencies on each other. This means that changes that affect multiple repositories need handling with extra care.

LFRic Apps and the UM both act as top level parents to a number of child repositories such as JULES, UKCA, SOCRATES and CASIM. These child repositories work independently as well as being used by the parent repositories. LFRic Apps also utilises the infrastructure in LFRic Core.

This means that changes to the science code in any of the child repositories will need testing with both the UM and LFRic Apps to check for any interactions.

Note

From LFRic Apps vn2.1 and UM vn13.8 there are duplicate copies of the physics code in both the UM and LFRic Apps.

Consideration should be made as to whether changes to the physics schemes are best made in LFRic Apps, the UM or both. If in doubt then the copy in LFRic Apps is considered the master version.

../_images/repos.png ../_images/repos_dark.png

Preparing Linked Tickets#

Every repository in a set of linked changes requires a ticket. Guidance on setting these up can be found in Create a Ticket. These tickets will be treated as a group with the same reviewers and committed at the same time.

Do:

  • Make sure every ticket has a cross reference to the others in the set, e.g. um:#1234

  • Use Commonly-Used Keywords to show which other repositories are involved

  • Get the tickets ready for review at the same time

  • Ask for help testing if you don’t have access to all the codebases involved

Important

Code branches in linked tickets will require branching from compatible revisions to ensure they work together.

If working with branches from a release then all repositories will be tagged with suitable keywords, e.g. for UM vn13.0, other repositories are also tagged with um13.0.

For head of trunk revisions make sure that all branches/revisions being used are at least as recent as the versions listed in the _rev parameter of <lfric_apps_trunk>/dependencies.sh, or <um_trunk>/rose-stem/rose-suite.conf.

If in doubt, please contact the Simulation Systems and Deployment Team for advice.

Multi-Repo Testing#

Please see this page for details on how to test multiple repositories together.