diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3e759fd9..b4ea826d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,19 +2,21 @@
 name: CI
 
 on:
+  push:
+    branches: [develop]
   pull_request:
     branches: [develop]
 
+env:
+  REPO: ${{ github.event.repository.name }}
+  BUNDLE: pr-${{ github.event.number }}
+
 jobs:
   build1:
     name: gnu 11.3.1 (UKMO)
     if: github.repository_owner == 'MetOffice'
     runs-on: jedi-self-hosted-rg
-
-    env:
-      REPO: ${{ github.event.repository.name }}
-      BUNDLE: pr-${{ github.event.number }}
-
+    
     steps:
       - name: pre-submit cleanup
         run: |
@@ -81,10 +83,6 @@ jobs:
     if: github.repository_owner == 'MetOffice'
     runs-on: ubuntu-latest
 
-    env:
-      REPO: ${{ github.event.repository.name }}
-      BUNDLE: pr-${{ github.event.number }}
-
     steps:
       - name: checkout current
         uses: actions/checkout@v4
@@ -138,3 +136,62 @@ jobs:
             --workdir=/usr/local/src/${REPO}/${BUNDLE} \
             --volume ${PWD}/${BUNDLE}:/usr/local/src/${REPO}/${BUNDLE} \
             'jcsda/docker-gnu-openmpi-dev:latest'
+
+  build3:
+    name: clang 10.0.0 (JCSDA)
+    if: github.repository_owner == 'MetOffice'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: checkout current
+        uses: actions/checkout@v4
+        with:
+          path: ./${{ env.BUNDLE }}/${{ env.REPO }}
+      - name: initiate bundle
+        run: cp ./${{ env.BUNDLE }}/${{ env.REPO }}/ci/* ./${{ env.BUNDLE }}/
+
+      - name: checkout jedicmake
+        uses: actions/checkout@v4
+        with:
+          path: ./${{ env.BUNDLE }}/jedicmake
+          repository: JCSDA-internal/jedi-cmake
+          submodules: true
+          token: ${{ secrets.GH_PAT }}
+
+      - name: checkout oops
+        uses: actions/checkout@v4
+        with:
+          path: ./${{ env.BUNDLE }}/oops
+          repository: JCSDA-internal/oops
+          token: ${{ secrets.GH_PAT }}
+      - name: matching branch checkout attempt oops ${{ github.head_ref }}
+        if: github.event_name == 'pull_request'
+        run: ./${{ env.BUNDLE }}/get-ref-branch ./${{ env.BUNDLE }}/oops
+
+      - name: checkout ioda
+        uses: actions/checkout@v4
+        with:
+          path: ./${{ env.BUNDLE }}/ioda
+          repository: JCSDA-internal/ioda
+          token: ${{ secrets.GH_PAT }}
+      - name: matching branch checkout attempt ioda ${{ github.head_ref }}
+        if: github.event_name == 'pull_request'
+        run: ./${{ env.BUNDLE }}/get-ref-branch ./${{ env.BUNDLE }}/ioda
+
+      - name: checkout ufo
+        uses: actions/checkout@v4
+        with:
+          path: ./${{ env.BUNDLE }}/ufo
+          repository: JCSDA-internal/ufo
+          token: ${{ secrets.GH_PAT }}
+      - name: matching branch checkout attempt ufo ${{ github.head_ref }}
+        if: github.event_name == 'pull_request'
+        run: ./${{ env.BUNDLE }}/get-ref-branch ./${{ env.BUNDLE }}/ufo
+
+      - name: build and test
+        run: |
+          docker run --rm \
+            --entrypoint=/usr/local/src/${REPO}/${BUNDLE}/build-and-test \
+            --workdir=/usr/local/src/${REPO}/${BUNDLE} \
+            --volume ${PWD}/${BUNDLE}:/usr/local/src/${REPO}/${BUNDLE} \
+            'jcsda/docker-clang-mpich-dev:latest'
diff --git a/ci/build-and-test b/ci/build-and-test
index 2320be3e..975c5c93 100755
--- a/ci/build-and-test
+++ b/ci/build-and-test
@@ -2,7 +2,7 @@
 #
 # (C) Crown Copyright 2023, the Met Office. All rights reserved.
 #
-set -euxo pipefail
+set -euo pipefail
 
 finally() {
     trap '' ERR
@@ -13,34 +13,36 @@ finally() {
     fi
 }
 
+# -- HERE is /usr/local/src/<REPONAME>/pr-<#> (cf ../.github/workflow/ci.yml)
 HERE="$(cd "$(dirname "$0")" && pwd)"
 THIS="$(basename "$0")"
 NPROC=${NPROC:-$(nproc)}
 WORKD="$(mktemp -d "${THIS}-XXXXXX" -t)"
 GENERATOR=Unix\ Makefiles
 if command -v ninja &>/dev/null; then GENERATOR=Ninja; fi
+BASE="${HERE%/*}"
+TESTDIR="${BASE##*/}"
+export OMPI_MCA_rmaps_base_oversubscribe=true
 
 trap finally ERR EXIT
 
 cd "${WORKD}"
 
-# If using JCSDA Docker container
+# -- Activate spack env if using JCSDA Docker container
 if [[ -f /opt/spack-environment/activate.sh ]]; then
     source /opt/spack-environment/activate.sh
 fi
 
 # -- Configure
-cmake -B . -S "${HERE}" -G "${GENERATOR}" \
-    -DCMAKE_BUILD_TYPE=Debug \
-    -DMPI_ARGS="--oversubscribe"
+cmake -B . -S "${HERE}" -G "${GENERATOR}" -DCMAKE_BUILD_TYPE=Debug
 
 # -- Build
 cmake --build . -j "${NPROC}"
 
 # -- Test
 env OMPI_ALLOW_RUN_AS_ROOT=1 OMPI_ALLOW_RUN_AS_ROOT_CONFIRM=1 \
-    ctest -j"${NPROC}" --test-dir './opsinputs' --output-on-failure ||\
+    ctest -j"${NPROC}" --test-dir "${TESTDIR}" || \
 env OMPI_ALLOW_RUN_AS_ROOT=1 OMPI_ALLOW_RUN_AS_ROOT_CONFIRM=1 \
-    ctest --test-dir './opsinputs' --rerun-failed -V
+    ctest --test-dir "${TESTDIR}" --rerun-failed -V
 
 exit