diff --git a/.github/workflows/core.yml b/.github/workflows/core.yml
index e738561b9c..67d50d1046 100644
--- a/.github/workflows/core.yml
+++ b/.github/workflows/core.yml
@@ -230,143 +230,143 @@ jobs:
           firedrake-check
         timeout-minutes: 5
 
-      - name: Run TSFC tests
-        # Run even if earlier tests failed
-        if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
-        run: |
-          . venv/bin/activate
-          : # Use pytest-xdist here so we can have a single collated output (not possible
-          : # for parallel tests)
-          firedrake-run-split-tests 1 1 -n 8 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/tsfc
-        timeout-minutes: 10
-
-      - name: Run PyOP2 tests
-        if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
-        run: |
-          . venv/bin/activate
-          : # Use pytest-xdist here so we can have a single collated output (not possible
-          : # for parallel tests)
-          firedrake-run-split-tests 1 1 -n 8 "$EXTRA_PYTEST_ARGS" --timeout 30 firedrake-repo/tests/pyop2
-          firedrake-run-split-tests 2 4 "$EXTRA_PYTEST_ARGS" --timeout 30 firedrake-repo/tests/pyop2
-          firedrake-run-split-tests 3 2 "$EXTRA_PYTEST_ARGS" --timeout 30 firedrake-repo/tests/pyop2
-          firedrake-run-split-tests 4 2 "$EXTRA_PYTEST_ARGS" --timeout 30 firedrake-repo/tests/pyop2
-        timeout-minutes: 10
-
-
-      - name: Run Firedrake tests (nprocs = 1)
-        if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
-        run: |
-          . venv/bin/activate
-          : # Use pytest-xdist here so we can have a single collated output (not possible
-          : # for parallel tests)
-          firedrake-run-split-tests 1 1 -n 8 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
-        timeout-minutes: 90
+      # - name: Run TSFC tests
+      #   # Run even if earlier tests failed
+      #   if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
+      #   run: |
+      #     . venv/bin/activate
+      #     : # Use pytest-xdist here so we can have a single collated output (not possible
+      #     : # for parallel tests)
+      #     firedrake-run-split-tests 1 1 -n 8 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/tsfc
+      #   timeout-minutes: 10
+      #
+      # - name: Run PyOP2 tests
+      #   if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
+      #   run: |
+      #     . venv/bin/activate
+      #     : # Use pytest-xdist here so we can have a single collated output (not possible
+      #     : # for parallel tests)
+      #     firedrake-run-split-tests 1 1 -n 8 "$EXTRA_PYTEST_ARGS" --timeout 30 firedrake-repo/tests/pyop2
+      #     firedrake-run-split-tests 2 4 "$EXTRA_PYTEST_ARGS" --timeout 30 firedrake-repo/tests/pyop2
+      #     firedrake-run-split-tests 3 2 "$EXTRA_PYTEST_ARGS" --timeout 30 firedrake-repo/tests/pyop2
+      #     firedrake-run-split-tests 4 2 "$EXTRA_PYTEST_ARGS" --timeout 30 firedrake-repo/tests/pyop2
+      #   timeout-minutes: 10
+
+
+      # - name: Run Firedrake tests (nprocs = 1)
+      #   if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
+      #   run: |
+      #     . venv/bin/activate
+      #     : # Use pytest-xdist here so we can have a single collated output (not possible
+      #     : # for parallel tests)
+      #     firedrake-run-split-tests 1 1 -n 8 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
+      #   timeout-minutes: 90
 
       - name: Run tests (nprocs = 2)
         if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
         run: |
           . venv/bin/activate
           firedrake-run-split-tests 2 4 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
-        timeout-minutes: 60
-
-      - name: Run tests (nprocs = 3)
-        if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
-        run: |
-          . venv/bin/activate
-          firedrake-run-split-tests 3 2 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
-        timeout-minutes: 60
-
-      - name: Run tests (nprocs = 4)
-        if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
-        run: |
-          . venv/bin/activate
-          firedrake-run-split-tests 4 2 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
-        timeout-minutes: 15
-
-      - name: Run tests (nprocs = 5)
-        if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
-        run: |
-          . venv/bin/activate
-          firedrake-run-split-tests 5 1 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
-        timeout-minutes: 15
-
-      - name: Run tests (nprocs = 6)
-        if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
-        run: |
-          . venv/bin/activate
-          firedrake-run-split-tests 6 1 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
-        timeout-minutes: 15
-
-      - name: Run tests (nprocs = 7)
-        if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
-        run: |
-          . venv/bin/activate
-          firedrake-run-split-tests 7 1 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
-        timeout-minutes: 15
-
-      - name: Run tests (nprocs = 8)
-        if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
-        run: |
-          . venv/bin/activate
-          firedrake-run-split-tests 8 1 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
-        timeout-minutes: 15
-
-      - name: Run Gusto smoke tests
-        # Only test Gusto in real mode
-        if: |
-          inputs.run_tests &&
-          (success() || steps.install.conclusion == 'success') &&
-          matrix.arch == 'default'
-        run: |
-          . venv/bin/activate
-          if [ ${{ inputs.target_branch }} = 'release' ]; then
-            GUSTO_BRANCH='main'
-          else
-            GUSTO_BRANCH='future'
-          fi
-          git clone --depth 1 https://github.com/firedrakeproject/gusto.git gusto-repo --branch $GUSTO_BRANCH
-          pip install --verbose ./gusto-repo
-          python -m pytest -n 8 --verbose \
-            gusto-repo/integration-tests/balance/test_saturated_balance.py \
-            gusto-repo/integration-tests/equations/test_thermal_sw.py \
-            gusto-repo/integration-tests/transport/test_embedded_dg_advection.py
-        timeout-minutes: 10
-
-      - name: Run Thetis smoke tests
-        if: |
-          inputs.run_tests &&
-          (success() || steps.install.conclusion == 'success') &&
-          matrix.arch == 'default'
-        run: |
-          . venv/bin/activate
-          git clone --depth 1 https://github.com/thetisproject/thetis.git thetis-repo --branch ${{ inputs.target_branch }}
-          pip install --verbose ./thetis-repo
-          python -m pytest -n 8 --verbose thetis-repo/test_adjoint/test_swe_adjoint.py
-        timeout-minutes: 10
-
-      - name: Run spyro smoke tests
-        if: |
-          inputs.run_tests &&
-          (success() || steps.install.conclusion == 'success') &&
-          matrix.arch == 'default'
-        run: |
-          . venv/bin/activate
-          git clone --depth 1 https://github.com/NDF-Poli-USP/spyro.git spyro-repo
-          pip install --verbose ./spyro-repo
-          mpiexec -n 6 python -m pytest spyro-repo/test_integration/ -m parallel[6]
-        timeout-minutes: 5
-
-      - name: Run G-ADOPT smoke tests
-        if: |
-          inputs.run_tests &&
-          (success() || steps.install.conclusion == 'success') &&
-          matrix.arch == 'default'
-        run: |
-          . venv/bin/activate
-          git clone --depth 1 https://github.com/g-adopt/g-adopt.git g-adopt-repo --branch ${{ inputs.target_branch }}
-          pip install --verbose ./g-adopt-repo
-          make -C g-adopt-repo/demos/mantle_convection/base_case check
-        timeout-minutes: 5
+        timeout-minutes: 240
+
+      # - name: Run tests (nprocs = 3)
+      #   if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
+      #   run: |
+      #     . venv/bin/activate
+      #     firedrake-run-split-tests 3 2 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
+      #   timeout-minutes: 60
+      #
+      # - name: Run tests (nprocs = 4)
+      #   if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
+      #   run: |
+      #     . venv/bin/activate
+      #     firedrake-run-split-tests 4 2 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
+      #   timeout-minutes: 15
+      #
+      # - name: Run tests (nprocs = 5)
+      #   if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
+      #   run: |
+      #     . venv/bin/activate
+      #     firedrake-run-split-tests 5 1 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
+      #   timeout-minutes: 15
+      #
+      # - name: Run tests (nprocs = 6)
+      #   if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
+      #   run: |
+      #     . venv/bin/activate
+      #     firedrake-run-split-tests 6 1 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
+      #   timeout-minutes: 15
+      #
+      # - name: Run tests (nprocs = 7)
+      #   if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
+      #   run: |
+      #     . venv/bin/activate
+      #     firedrake-run-split-tests 7 1 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
+      #   timeout-minutes: 15
+      #
+      # - name: Run tests (nprocs = 8)
+      #   if: inputs.run_tests && (success() || steps.install.conclusion == 'success')
+      #   run: |
+      #     . venv/bin/activate
+      #     firedrake-run-split-tests 8 1 "$EXTRA_PYTEST_ARGS" firedrake-repo/tests/firedrake
+      #   timeout-minutes: 15
+      #
+      # - name: Run Gusto smoke tests
+      #   # Only test Gusto in real mode
+      #   if: |
+      #     inputs.run_tests &&
+      #     (success() || steps.install.conclusion == 'success') &&
+      #     matrix.arch == 'default'
+      #   run: |
+      #     . venv/bin/activate
+      #     if [ ${{ inputs.target_branch }} = 'release' ]; then
+      #       GUSTO_BRANCH='main'
+      #     else
+      #       GUSTO_BRANCH='future'
+      #     fi
+      #     git clone --depth 1 https://github.com/firedrakeproject/gusto.git gusto-repo --branch $GUSTO_BRANCH
+      #     pip install --verbose ./gusto-repo
+      #     python -m pytest -n 8 --verbose \
+      #       gusto-repo/integration-tests/balance/test_saturated_balance.py \
+      #       gusto-repo/integration-tests/equations/test_thermal_sw.py \
+      #       gusto-repo/integration-tests/transport/test_embedded_dg_advection.py
+      #   timeout-minutes: 10
+      #
+      # - name: Run Thetis smoke tests
+      #   if: |
+      #     inputs.run_tests &&
+      #     (success() || steps.install.conclusion == 'success') &&
+      #     matrix.arch == 'default'
+      #   run: |
+      #     . venv/bin/activate
+      #     git clone --depth 1 https://github.com/thetisproject/thetis.git thetis-repo --branch ${{ inputs.target_branch }}
+      #     pip install --verbose ./thetis-repo
+      #     python -m pytest -n 8 --verbose thetis-repo/test_adjoint/test_swe_adjoint.py
+      #   timeout-minutes: 10
+      #
+      # - name: Run spyro smoke tests
+      #   if: |
+      #     inputs.run_tests &&
+      #     (success() || steps.install.conclusion == 'success') &&
+      #     matrix.arch == 'default'
+      #   run: |
+      #     . venv/bin/activate
+      #     git clone --depth 1 https://github.com/NDF-Poli-USP/spyro.git spyro-repo
+      #     pip install --verbose ./spyro-repo
+      #     mpiexec -n 6 python -m pytest spyro-repo/test_integration/ -m parallel[6]
+      #   timeout-minutes: 5
+      #
+      # - name: Run G-ADOPT smoke tests
+      #   if: |
+      #     inputs.run_tests &&
+      #     (success() || steps.install.conclusion == 'success') &&
+      #     matrix.arch == 'default'
+      #   run: |
+      #     . venv/bin/activate
+      #     git clone --depth 1 https://github.com/g-adopt/g-adopt.git g-adopt-repo --branch ${{ inputs.target_branch }}
+      #     pip install --verbose ./g-adopt-repo
+      #     make -C g-adopt-repo/demos/mantle_convection/base_case check
+      #   timeout-minutes: 5
 
       - name: Upload log files
         uses: actions/upload-artifact@v4
diff --git a/tests/firedrake/regression/test_covariance_operator.py b/tests/firedrake/regression/test_covariance_operator.py
index 4a5ab20257..38ede96759 100644
--- a/tests/firedrake/regression/test_covariance_operator.py
+++ b/tests/firedrake/regression/test_covariance_operator.py
@@ -32,6 +32,12 @@ def rng():
     return RandomGenerator(PCG64(seed=13))
 
 
+@pytest.fixture(autouse=True)
+def garbage_cleanup():
+    yield
+    PETSc.garbage_cleanup(COMM_WORLD)
+
+
 @pytest.mark.skipcomplex
 @pytest.mark.parallel([1, 2])
 @pytest.mark.parametrize("degree", (1, 2), ids=["degree1", "degree2"])