mergeback from main

.git_archival.txt

@@ -0,0 +1,4 @@
+node: $Format:%H$
+node-date: $Format:%cI$
+describe-name: $Format:%(describe:tags=true)$
+ref-names: $Format:%D$

.gitattributes

@@ -0,0 +1 @@
+.git_archival.txt  export-subst

.github/ISSUE_TEMPLATE/config.yml

@@ -4,3 +4,6 @@ contact_links:
   -  name: 💬 Iris GitHub Discussions
      url: https://github.com/SciTools/iris/discussions
      about: Engage with the Iris community to discuss your issue
+  -  name: ❓ Usage Question
+     url: https://github.com/SciTools/iris/discussions/categories/q-a
+     about: Raise a question about how to use Iris in the Q&A section of Discussions

.github/workflows/benchmark.yml

@@ -6,6 +6,12 @@ on:
   schedule:
     # Runs every day at 23:00.
     - cron: "0 23 * * *"
+  workflow_dispatch:
+    inputs:
+      first_commit:
+        description: "Argument to be passed to the overnight benchmark script."
+        required: false
+        type: string
 
 jobs:
   benchmark:
@@ -15,7 +21,7 @@ jobs:
     env:
       IRIS_TEST_DATA_LOC_PATH: benchmarks
       IRIS_TEST_DATA_PATH: benchmarks/iris-test-data
-      IRIS_TEST_DATA_VERSION: "2.14"
+      IRIS_TEST_DATA_VERSION: "2.15"
       # Lets us manually bump the cache to rebuild
       ENV_CACHE_BUILD: "0"
       TEST_DATA_CACHE_BUILD: "2"
@@ -64,7 +70,12 @@ jobs:
 
       - name: Run overnight benchmarks
         run: |
-          first_commit=$(git log --after="$(date -d "1 day ago" +"%Y-%m-%d") 23:00:00" --pretty=format:"%h" | tail -n 1)
+          first_commit=${{ inputs.first_commit }}
+          if [ "$first_commit" == "" ]
+          then
+            first_commit=$(git log --after="$(date -d "1 day ago" +"%Y-%m-%d") 23:00:00" --pretty=format:"%h" | tail -n 1)
+          fi
+
           if [ "$first_commit" != "" ]
           then
             nox --session="benchmarks(overnight)" -- $first_commit

.github/workflows/ci-tests.yml

@@ -3,7 +3,7 @@
 #   - https://github.com/actions/checkout
 #   - https://github.com/marketplace/actions/setup-miniconda
 
-name: ci-tests 
+name: ci-tests
 
 on:
   push:
@@ -23,7 +23,7 @@ concurrency:
 
 jobs:
   tests:
-    name: "${{ matrix.session }} ${{ matrix.os }} py${{ matrix.python-version }}"
+    name: "${{ matrix.session }} (py${{ matrix.python-version }} ${{ matrix.os }})"
 
     runs-on: ${{ matrix.os }}
 
@@ -35,11 +35,18 @@ jobs:
       fail-fast: false
       matrix:
         os: ["ubuntu-latest"]
-        python-version: ["3.8"]
-        session: ["tests"]
+        python-version: ["3.10"]
+        session: ["tests", "doctest", "gallery", "linkcheck"]
+        include:
+          - os: "ubuntu-latest"
+            python-version: "3.9"
+            session: "tests"
+          - os: "ubuntu-latest"
+            python-version: "3.8"
+            session: "tests"
 
     env:
-      IRIS_TEST_DATA_VERSION: "2.14"
+      IRIS_TEST_DATA_VERSION: "2.17"
       ENV_NAME: "ci-tests"
 
     steps:
@@ -57,14 +64,14 @@ jobs:
       - name: "data cache"
         uses: ./.github/workflows/composite/iris-data-cache
         with:
-          cache_build: 1
+          cache_build: 0
           env_name: ${{ env.ENV_NAME }}
           version: ${{ env.IRIS_TEST_DATA_VERSION }}
 
       - name: "conda package cache"
         uses: ./.github/workflows/composite/conda-pkg-cache
         with:
-          cache_build: 1
+          cache_build: 0
           cache_period: ${{ env.CACHE_PERIOD }}
           env_name: ${{ env.ENV_NAME }}
 
@@ -80,7 +87,7 @@ jobs:
       - name: "conda environment cache"
         uses: ./.github/workflows/composite/conda-env-cache
         with:
-          cache_build: 1
+          cache_build: 0
           cache_period: ${{ env.CACHE_PERIOD }}
           env_name: ${{ env.ENV_NAME }}
           install_packages: "cartopy nox pip"
@@ -93,28 +100,34 @@ jobs:
       - name: "cartopy cache"
         uses: ./.github/workflows/composite/cartopy-cache
         with:
-          cache_build: 1
+          cache_build: 0
           cache_period: ${{ env.CACHE_PERIOD }}
           env_name: ${{ env.ENV_NAME }}
 
       - name: "nox cache"
         uses: ./.github/workflows/composite/nox-cache
         with:
-          cache_build: 1
+          cache_build: 0
           env_name: ${{ env.ENV_NAME }}
           lock_file: ${{ env.LOCK_FILE }}
 
       # TODO: drop use of site.cfg and explicit use of mplrc
       - name: "iris configure"
         env:
           SITE_CFG: lib/iris/etc/site.cfg
+          MPL_RC: ${HOME}/.config/matplotlib/matplotlibrc
         run: |
           mkdir -p $(dirname ${SITE_CFG})
           echo ${SITE_CFG}
           echo "[Resources]" >> ${SITE_CFG}
           echo "test_data_dir = ${HOME}/iris-test-data/test_data" >> ${SITE_CFG}
           echo "doc_dir = ${GITHUB_WORKSPACE}/docs" >> ${SITE_CFG}
           cat ${SITE_CFG}
+          mkdir -p $(dirname ${MPL_RC})
+          echo ${MPL_RC}
+          echo "backend : agg" >> ${MPL_RC}
+          echo "image.cmap : viridis" >> ${MPL_RC}
+          cat ${MPL_RC}
 
       - name: "iris ${{ matrix.session }}"
         env: