diff --git a/.github/workflows/cd.yml b/.github/workflows/cd.yml
index 8785207..84bf87e 100644
--- a/.github/workflows/cd.yml
+++ b/.github/workflows/cd.yml
@@ -10,11 +10,11 @@ on:
 jobs:
   cd:
     name: CD
-    uses: access-nri/build-cd/.github/workflows/cd.yml@v7
+    uses: access-nri/build-cd/.github/workflows/cd.yml@v8
     with:
       model: ${{ vars.NAME }}
-      spack-manifest-schema-version: 1-0-7
-      config-versions-schema-version: 3-0-0
+      spack-manifest-schema-version: 2-0-0
+      config-versions-schema-version: 4-0-0
       config-packages-schema-version: 1-0-0
     permissions:
       contents: write
diff --git a/.github/workflows/ci-command.yml b/.github/workflows/ci-command.yml
index b06012e..9d74435 100644
--- a/.github/workflows/ci-command.yml
+++ b/.github/workflows/ci-command.yml
@@ -8,12 +8,11 @@ jobs:
   redeploy:
     name: Redeploy
     if: startsWith(github.event.comment.body, '!redeploy') && github.event.issue.pull_request
-    uses: access-nri/build-cd/.github/workflows/ci.yml@v7
+    uses: access-nri/build-cd/.github/workflows/ci.yml@v8
     with:
       model: ${{ vars.NAME }}
-      pr: ${{ github.event.issue.number }}
-      spack-manifest-schema-version: 1-0-7
-      config-versions-schema-version: 3-0-0
+      spack-manifest-schema-version: 2-0-0
+      config-versions-schema-version: 4-0-0
       config-packages-schema-version: 1-0-0
     permissions:
       pull-requests: write
@@ -23,7 +22,7 @@ jobs:
   bump:
     name: Bump
     if: startsWith(github.event.comment.body, '!bump') && github.event.issue.pull_request
-    uses: access-nri/build-cd/.github/workflows/ci-comment.yml@v7
+    uses: access-nri/build-cd/.github/workflows/ci-comment.yml@v8
     with:
       model: ${{ vars.NAME }}
     permissions:
@@ -33,7 +32,7 @@ jobs:
   configs:
     name: Configs
     if: startsWith(github.event.comment.body, '!update-configs') && github.event.issue.pull_request
-    uses: access-nri/build-cd/.github/workflows/ci-command-configs.yml@v7
+    uses: access-nri/build-cd/.github/workflows/ci-command-configs.yml@v8
     with:
       model: ${{ vars.NAME }}
       auto-configs-pr-schema-version: 1-0-0
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5d18be0..7abfac3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -19,15 +19,12 @@ on:
 jobs:
   pr-ci:
     name: CI
-    if: >-
-      github.event.action != 'closed'
-    uses: access-nri/build-cd/.github/workflows/ci.yml@v7
+    if: github.event.action != 'closed'
+    uses: access-nri/build-cd/.github/workflows/ci.yml@v8
     with:
       model: ${{ vars.NAME }}
-      # root-sbd: if different from vars.NAME
-      pr: ${{ github.event.pull_request.number }}
-      spack-manifest-schema-version: 1-0-7
-      config-versions-schema-version: 3-0-0
+      spack-manifest-schema-version: 2-0-0
+      config-versions-schema-version: 4-0-0
       config-packages-schema-version: 1-0-0
     permissions:
       pull-requests: write
@@ -37,7 +34,5 @@ jobs:
   pr-closed:
     name: Closed
     if: github.event.action == 'closed'
-    uses: access-nri/build-cd/.github/workflows/ci-closed.yml@v7
-    with:
-      root-sbd: ${{ vars.NAME }} # or something else, if different from vars.NAME
+    uses: access-nri/build-cd/.github/workflows/ci-closed.yml@v8
     secrets: inherit
diff --git a/config/versions.json b/config/versions.json
index 2a91c28..0ac7ad9 100644
--- a/config/versions.json
+++ b/config/versions.json
@@ -1,5 +1,5 @@
 {
-    "$schema": "https://raw.githubusercontent.com/ACCESS-NRI/schema/main/au.org.access-nri/model/deployment/config/versions/3-0-0.json",
-    "spack": "0.22",
-    "spack-packages": "2025.11.002"
+  "$schema": "https://raw.githubusercontent.com/ACCESS-NRI/schema/main/au.org.access-nri/model/deployment/config/versions/4-0-0.json",
+  "spack": "1.1",
+  "access-spack-packages": "2026.03.001"
 }
diff --git a/spack.yaml b/spack.yaml
index 2ab45ca..b41e54b 100644
--- a/spack.yaml
+++ b/spack.yaml
@@ -1,75 +1,93 @@
 spack:
+  definitions:
+  - _name: [access-issm]
+  - _version: [2025.11.0]
   specs:
-    - access-issm@git.2025.11.0
+  - access-issm
   packages:
     issm:
       require:
-        - '@git.2025.11.24'
-        - +wrappers
-        - +py-tools
-        - ~ad
+      - '@git.2025.11.24'
+      - +wrappers
+      - +py-tools
+      - ~ad
 
     python:
       require:
-        - '@3.11.7'
+      - '@3.11.14'
 
     py-numpy:
       require:
-        - '@1.26.4'
+      - '@1.26.4'
 
     openmpi:
       require:
-        - '@4.1.3'
+      - '@4.1.5'
 
     access-triangle:
       require:
-        - '@1.6.1'
+      - '@1.6.1'
 
     petsc:
       require:
-        - '@3.21.1'
+      - '@3.21.1'
 
     metis:
       require:
-        - '@5.1.0'
+      - '@5.1.0'
 
     mumps:
       require:
-        - '@5.6.2'
+      - '@5.6.2'
 
     parmetis:
       require:
-        - '@4.0.3'
+      - '@4.0.3'
 
-    scalapack:
+    netlib-scalapack:
       require:
-        - '@2.2.0'
+      - '@2.2.0'
 
     autoconf:
       require:
-        - '@2.72'
+      - '@2.72'
 
     automake:
       require:
-        - '@1.16.5'
+      - '@1.16.5'
 
     libtool:
       require:
-        - '@2.4.7'
+      - '@2.4.7'
 
     m4:
       require:
-        - '@1.4.19'
+      - '@1.4.19'
 
     m1qn3:
       require:
-        - '@3.3'
+      - '@3.3'
+
+    # Wokaround due to https://github.com/spack/spack-packages/pull/3644
+    re2c:
+      require:
+      - '@3.1'
+
+    # Compilers
+    c:
+      require:
+      - 'gcc@13.2.0'
+    cxx:
+      require:
+      - 'gcc@13.2.0'
+    fortran:
+      require:
+      - 'gcc@13.2.0'
 
     # “all” can remain empty if you aren’t forcing any particular compiler / MPI
     all:
-      require:
-        - '%gcc@13'
-        - 'target=x86_64'
+      prefer:
+      - 'target=x86_64'
   # Create a unified view of all installed packages
   view: true
   # Make the solver unify dependencies