Move supported toplevel toolchains from eb_hooks.py into a separate JSON for easier define-once-and-reuse

.github/workflows/test-eb-hooks.yml

@@ -51,6 +51,28 @@ jobs:
               module load EESSI-extend
               diff "$TEMP_FILE" "$EASYBUILD_HOOKS"
 
+        - name: Check whether eessi_supported_toolchains.json (used by eb_hooks.py) is up-to-date
+          if: ${{ github.event_name == 'pull_request' }}
+          run: |
+              FILE="eessi_supported_toolchains.json"
+              TEMP_FILE="$(mktemp)"
+
+              # Fetch base branch
+              git fetch origin ${{ github.base_ref }}
+
+              # Check if the file has changed in the PR
+              if git diff --name-only origin/${{ github.base_ref }}...HEAD | grep -q "^$FILE$"; then
+                echo "$FILE changed in PR. Using PR version."
+                cp "$FILE" "$TEMP_FILE"
+              else
+                echo "File not changed in PR. Using default branch version."
+                git show origin/${{ github.base_ref }}:$FILE > "$TEMP_FILE"
+              fi
+
+              # Compare to what is shipped next to the hooks in the repository
+              module load EESSI-extend
+              diff "$TEMP_FILE" "$(dirname $EASYBUILD_HOOKS)/$FILE"
+
   check_eb_hooks_functionality:
     runs-on: ubuntu-24.04
     strategy:

eb_hooks.py

@@ -67,31 +67,32 @@
 
 STACK_REPROD_SUBDIR = 'reprod'
 
-EESSI_SUPPORTED_TOP_LEVEL_TOOLCHAINS = {
-    '2023.06': [
-        {'name': 'foss', 'version': '2022b'},
-        {'name': 'foss', 'version': '2023a'},
-        {'name': 'foss', 'version': '2023b'},
-    ],
-    '2025.06': [
-        {'name': 'foss', 'version': '2024a'},
-        {'name': 'foss', 'version': '2025a'},
-        {'name': 'foss', 'version': '2025b'},
-    ],
-    '2026.06': [
-        {'name': 'foss', 'version': '2026.1'},
-        {'name': 'lfoss', 'version': '2026.1'},
-    ],
-}
-if EASYBUILD_VERSION >= '5.2.0':
-    EESSI_SUPPORTED_TOP_LEVEL_TOOLCHAINS['2025.06'].append(
-        {'name': 'lfoss', 'version': '2025b'}
-    )
 
-if EASYBUILD_VERSION >= '5.3.1':
-    EESSI_SUPPORTED_TOP_LEVEL_TOOLCHAINS['2025.06'].append(
-        {'name': 'rompi', 'version': '2025a'}
-    )
+def load_supported_top_level_toolchains():
+    """
+    Load the supported top-level toolchains per EESSI version from eessi_supported_toolchains.json,
+    which is located next to this hooks file (both in the software-layer-scripts repository, and when installed
+    in <EESSI prefix>/init/easybuild). Toolchains that require a more recent EasyBuild version than the one
+    being used (as specified via 'min_easybuild_version') are left out.
+    """
+    toolchains_file = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'eessi_supported_toolchains.json')
+    try:
+        with open(toolchains_file) as fh:
+            toolchains = json.load(fh)
+    except (OSError, ValueError) as err:
+        raise EasyBuildError(f"Failed to load supported toolchains from {toolchains_file} "
+                             f"(it is expected to be located next to the EasyBuild hooks file): {err}")
+
+    return {
+        eessi_version: [
+            {'name': tc['name'], 'version': tc['version']} for tc in tcs
+            if EASYBUILD_VERSION >= tc.get('min_easybuild_version', '0')
+        ]
+        for eessi_version, tcs in toolchains.items()
+    }
+
+
+EESSI_SUPPORTED_TOP_LEVEL_TOOLCHAINS = load_supported_top_level_toolchains()
 
 # Supported compute capabilities by CUDA toolkit version
 # Obtained by installing all CUDAs from 12.0.0 to 13.3.0, then using:

eessi_supported_toolchains.json

@@ -0,0 +1,18 @@
+{
+    "2023.06": [
+        {"name": "foss", "version": "2022b"},
+        {"name": "foss", "version": "2023a"},
+        {"name": "foss", "version": "2023b"}
+    ],
+    "2025.06": [
+        {"name": "foss", "version": "2024a"},
+        {"name": "foss", "version": "2025a"},
+        {"name": "foss", "version": "2025b"},
+        {"name": "lfoss", "version": "2025b", "min_easybuild_version": "5.2.0"},
+        {"name": "rompi", "version": "2025a", "min_easybuild_version": "5.3.1"}
+    ],
+    "2026.06": [
+        {"name": "foss", "version": "2026.1"},
+        {"name": "lfoss", "version": "2026.1"}
+    ]
+}

install_scripts.sh

@@ -225,6 +225,7 @@ fi
 # Copy over EasyBuild hooks file used for installations
 hook_files=(
     eb_hooks.py
+    eessi_supported_toolchains.json
 )
 copy_files_by_list ${TOPDIR} ${INSTALL_PREFIX}/init/easybuild "${hook_files[@]}"