Merge branch 'main' into feature/mathomp4/v11-update-mapl-2.51.2

.circleci/config.yml

@@ -15,7 +15,7 @@ parameters:
     default: ""
 
 # Anchors to prevent forgetting to update a version
-os_version: &os_version ubuntu20
+os_version: &os_version ubuntu24
 baselibs_version: &baselibs_version v7.27.0
 bcs_version: &bcs_version v11.6.0
 tag_build_arg_name: &tag_build_arg_name gcmversion

.github/workflows/workflow.yml

@@ -19,7 +19,7 @@ jobs:
     if: "!contains(github.event.pull_request.labels.*.name, '0 diff trivial')"
     runs-on: ubuntu-latest
     container:
-      image: gmao/ubuntu20-geos-env:v7.27.0-intelmpi_2021.13-ifort_2021.13
+      image: gmao/ubuntu24-geos-env:v7.27.0-intelmpi_2021.13-ifort_2021.13
       # Per https://github.com/actions/virtual-environments/issues/1445#issuecomment-713861495
       # It seems like we might not need secrets on GitHub Actions which is good for forked
       # pull requests

README.md

@@ -155,6 +155,20 @@ Note that when you first use `gh`, it will ask what your preferred git protocol
 is (https or ssh) to use "underneath". The caveats above will apply to whichever
 you choose.
 
+### Setting up `mepo` to use blobless clones
+
+The GEOS GCM uses a Python utility called [mepo](https://github.com/GEOS-ESM/mepo/) to manage **m**ultiple git r**epo**sitories instead of using other technologies like Git
+submodules. `mepo` uses a YAML file that provides a list of components (and their versions) that are required for a particular configuration of GEOS GCM.
+
+We *highly* recommend setting up `mepo` to use [blobless clones](https://github.blog/open-source/git/get-up-to-speed-with-partial-clone-and-shallow-clone/) to speed
+up cloning of the sub-repositories, especially on discover. To do this, there is a one-time command to run:
+
+```
+mepo config set clone.partial blobless
+```
+
+This will set up `mepo` to use blobless clones for all future clones by adding an entry to `~/.mepoconfig`.
+
 ---
 
 ### Single Step Building of the Model