From 21b0d82e45b5f90fda2fdeea460e362d56e3fd0b Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Thu, 24 Jul 2025 20:02:09 +0200
Subject: [PATCH 01/14] Use EasyBuild hooks to limit toolchains that can be
 used for specific EESSI version

---
 .github/workflows/test-eb-hooks.yml | 47 +++++++++++++++++-------
 eb_hooks.py                         | 57 ++++++++++++++++++++++++++---
 2 files changed, 84 insertions(+), 20 deletions(-)

diff --git a/.github/workflows/test-eb-hooks.yml b/.github/workflows/test-eb-hooks.yml
index 57b0d650..eeb82df5 100644
--- a/.github/workflows/test-eb-hooks.yml
+++ b/.github/workflows/test-eb-hooks.yml
@@ -13,26 +13,27 @@ jobs:
       matrix:
         EESSI_VERSION:
           - '2023.06'
+          - '2025.06'
+        include:
+          # For each EESSI version we need to test different modules
+          - EESSI_VERSION: '2023.06'
+            COMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-13.2.0.eb'
+            INCOMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-14.2.0.eb'
+          - EESSI_VERSION: '2025.06'
+            COMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-14.2.0.eb'
+            INCOMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-13.2.0.eb'
+
     steps:
         - name: Check out software-layer repository
           uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
           with:
               fetch-depth: 0  # Fetch all history for all branches and tags
 
-        - name: Show host system info
-          run: |
-            echo "/proc/cpuinfo:"
-            cat /proc/cpuinfo
-            echo
-            echo "lscpu:"
-            lscpu
-
-        - name: Mount EESSI CernVM-FS pilot repository
-          uses: cvmfs-contrib/github-action-cvmfs@55899ca74cf78ab874bdf47f5a804e47c198743c # v4.0
+        - name: Mount EESSI CernVM-FS repository
+          uses: eessi/github-action-eessi@v3
           with:
-              cvmfs_config_package: https://github.com/EESSI/filesystem-layer/releases/download/latest/cvmfs-config-eessi_latest_all.deb
-              cvmfs_http_proxy: DIRECT
-              cvmfs_repositories: software.eessi.io
+            eessi_stack_version: ${{matrix.EESSI_VERSION}}
+            use_eessi_module: true
 
         - name: Check that EasyBuild hook is up to date
           if: ${{ github.event_name == 'pull_request' }}
@@ -56,6 +57,24 @@ jobs:
               sed -i "s/<EESSI_VERSION>/${{matrix.EESSI_VERSION}}/g" "${TEMP_FILE}"
 
               # Compare the hooks to what is shipped in the repository
-              source /cvmfs/software.eessi.io/versions/${{matrix.EESSI_VERSION}}/init/bash
               module load EESSI-extend
               diff "$TEMP_FILE" "$EASYBUILD_HOOKS"
+
+        - name: Test that toolchain verification check works
+          if: ${{ github.event_name == 'pull_request' }}
+          run: |
+              # Set up some environment variables
+              export COMPATIBLE_EASYCONFIG=${{matrix.COMPATIBLE_EASYCONFIG}}
+              export INCOMPATIBLE_EASYCONFIG=${{matrix.INCOMPATIBLE_EASYCONFIG}}
+
+              # Load specific EESSI-extend vertsion (proxies a version check)
+              module load EESSI-extend/${{matrix.EESSI_VERSION}}-easybuild
+
+              # Test an easyconfig that should work
+              eb --hooks=$PWD/eb_hooks.py "$COMPATIBLE_EASYCONFIG" --stop fetch
+
+              # Pick an outdated toolchain for the negative test
+              eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch 2>&1 1>/dev/null | grep -q "not supported in EESSI"
+
+              # Check the override works
+              EESSI_OVERRIDE_TOOLCHAIN_CHECK=1 eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch
diff --git a/eb_hooks.py b/eb_hooks.py
index 91583ce0..97662b41 100644
--- a/eb_hooks.py
+++ b/eb_hooks.py
@@ -8,6 +8,7 @@
 import easybuild.tools.environment as env
 from easybuild.easyblocks.generic.configuremake import obtain_config_guess
 from easybuild.framework.easyconfig.constants import EASYCONFIG_CONSTANTS
+from easybuild.framework.easyconfig.easyconfig import get_toolchain_hierarchy
 from easybuild.tools import config
 from easybuild.tools.build_log import EasyBuildError, print_msg, print_warning
 from easybuild.tools.config import build_option, install_path, update_build_option
@@ -15,6 +16,7 @@
 from easybuild.tools.run import run_cmd
 from easybuild.tools.systemtools import AARCH64, POWER, X86_64, get_cpu_architecture, get_cpu_features
 from easybuild.tools.toolchain.compiler import OPTARCH_GENERIC
+from easybuild.tools.toolchain.toolchain import is_system_toolchain
 from easybuild.tools.version import VERSION as EASYBUILD_VERSION
 from easybuild.tools.modules import get_software_root_env_var_name
 
@@ -50,6 +52,18 @@
 
 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'},
+    ],
+}
+
 
 def is_gcccore_1220_based(**kwargs):
 # ecname, ecversion, tcname, tcversion):
@@ -128,6 +142,34 @@ def parse_hook(ec, *args, **kwargs):
     ec = inject_gpu_property(ec)
 
 
+def verify_toolchains_supported_by_eessi_version(easyconfigs):
+    """Each EESSI version supports a limited set of toolchains, sanity check the easyconfigs for toolchain support."""
+    eessi_version = get_eessi_envvar('EESSI_VERSION')
+    supported_eessi_toolchains = []
+    for top_level_toolchain in EESSI_SUPPORTED_TOP_LEVEL_TOOLCHAINS[eessi_version]:
+        supported_eessi_toolchains += get_toolchain_hierarchy(top_level_toolchain)
+    for ec in easyconfigs:
+        toolchain = ec['ec']['toolchain']
+        # if it is a system toolchain or appears in the list, we are all good
+        if is_system_toolchain(toolchain['name']):
+            continue
+        elif not any(toolchain.items() <= supported.items() for supported in supported_eessi_toolchains):
+            raise EasyBuildError(
+                f"Toolchain {toolchain} (required by {ec['full_mod_name']}) is not supported in EESSI/{eessi_version}\n"
+                f"Supported toolchains are:\n" + "\n".join(sorted("  " + str(tc) for tc in supported_eessi_toolchains))
+            )
+
+
+def pre_build_and_install_loop_hook(easyconfigs):
+    """Main pre_build_and_install_loop hook: trigger custom functions before beginning installation loop."""
+
+    # Always check that toolchain supported by the EESSI version (unless overridden)
+    if os.getenv("EESSI_OVERRIDE_TOOLCHAIN_CHECK"):
+        print_warning("Overriding the check that the toolchains are supported by the EESSI version.")
+    else:
+        verify_toolchains_supported_by_eessi_version(easyconfigs)
+
+
 def post_ready_hook(self, *args, **kwargs):
     """
     Post-ready hook: limit parallellism for selected builds based on software name and CPU target.
@@ -135,7 +177,10 @@ def post_ready_hook(self, *args, **kwargs):
     """
     # 'parallel' easyconfig parameter (EB4) or the parallel property (EB5) is set via EasyBlock.set_parallel
     # in ready step based on available cores
-    parallel = getattr(self, 'parallel', self.cfg['parallel'])
+    if hasattr(self, 'parallel'):
+        parallel = self.parallel
+    else:
+        parallel = self.cfg['parallel']
     
     if parallel == 1:
         return  # no need to limit if already using 1 core
@@ -167,8 +212,8 @@ def post_ready_hook(self, *args, **kwargs):
 
     # apply the limit if it's different from current
     if new_parallel != parallel:
-        if EASYBUILD_VERSION >= '5':
-            self.cfg.parallel = new_parallel
+        if hasattr(self, 'parallel'):
+            self.parallel = new_parallel
         else:
             self.cfg['parallel'] = new_parallel
         msg = "limiting parallelism to %s (was %s) for %s on %s to avoid out-of-memory failures during building/testing"
@@ -394,7 +439,7 @@ def parse_hook_freeimage_aarch64(ec, *args, **kwargs):
     https://github.com/EESSI/software-layer/pull/736#issuecomment-2373261889
     """
     if ec.name == 'FreeImage' and ec.version in ('3.18.0',):
-        if os.getenv('EESSI_CPU_FAMILY') == 'aarch64':
+        if get_eessi_envvar('EESSI_CPU_FAMILY') == 'aarch64':
             # Make sure the toolchainopts key exists, and the value is a dict,
             # before we add the option to enable PIC and disable PNG_ARM_NEON_OPT
             if 'toolchainopts' not in ec or ec['toolchainopts'] is None:
@@ -1230,7 +1275,7 @@ def replace_non_distributable_files_with_symlinks(log, install_dir, pkg_name, al
                     # CUDA and cu* libraries themselves don't care about compute capability so remove this
                     # duplication from under host_injections (symlink to a single CUDA or cu* library
                     # installation for all compute capabilities)
-                    accel_subdir = os.getenv("EESSI_ACCELERATOR_TARGET")
+                    accel_subdir = get_eessi_envvar("EESSI_ACCELERATOR_TARGET")
                     if accel_subdir:
                         host_inj_path = host_inj_path.replace("/accel/%s" % accel_subdir, '')
                     # make sure source and target of symlink are not the same
@@ -1326,7 +1371,7 @@ def post_easyblock_hook(self, *args, **kwargs):
 
         # Always trigger this one for EESSI CVMFS/site installations and version 2025.06 or newer, regardless of self.name
         if os.getenv('EESSI_CVMFS_INSTALL') or os.getenv('EESSI_SITE_INSTALL'):
-            if os.getenv('EESSI_VERSION') and LooseVersion(os.getenv('EESSI_VERSION')) >= '2025.06':
+            if get_eessi_envvar('EESSI_VERSION') and LooseVersion(get_eessi_envvar('EESSI_VERSION')) >= '2025.06':
                 post_easyblock_hook_copy_easybuild_subdir(self, *args, **kwargs)
         else:
             self.log.debug("No CVMFS/site installation requested, not running post_easyblock_hook_copy_easybuild_subdir.")

From b49b1f98b0a402877e63c7f09a7290d5dd8ac8f8 Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Thu, 24 Jul 2025 20:06:01 +0200
Subject: [PATCH 02/14] Run the up-to-date check last

---
 .github/workflows/test-eb-hooks.yml | 38 ++++++++++++++---------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/.github/workflows/test-eb-hooks.yml b/.github/workflows/test-eb-hooks.yml
index eeb82df5..9a0a748c 100644
--- a/.github/workflows/test-eb-hooks.yml
+++ b/.github/workflows/test-eb-hooks.yml
@@ -35,6 +35,25 @@ jobs:
             eessi_stack_version: ${{matrix.EESSI_VERSION}}
             use_eessi_module: true
 
+        - name: Test that toolchain verification check works
+          if: ${{ github.event_name == 'pull_request' }}
+          run: |
+              # Set up some environment variables
+              export COMPATIBLE_EASYCONFIG=${{matrix.COMPATIBLE_EASYCONFIG}}
+              export INCOMPATIBLE_EASYCONFIG=${{matrix.INCOMPATIBLE_EASYCONFIG}}
+
+              # Load specific EESSI-extend vertsion (proxies a version check)
+              module load EESSI-extend/${{matrix.EESSI_VERSION}}-easybuild
+
+              # Test an easyconfig that should work
+              eb --hooks=$PWD/eb_hooks.py "$COMPATIBLE_EASYCONFIG" --stop fetch
+
+              # Pick an outdated toolchain for the negative test
+              eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch 2>&1 1>/dev/null | grep -q "not supported in EESSI"
+
+              # Check the override works
+              EESSI_OVERRIDE_TOOLCHAIN_CHECK=1 eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch
+
         - name: Check that EasyBuild hook is up to date
           if: ${{ github.event_name == 'pull_request' }}
           run: |
@@ -59,22 +78,3 @@ jobs:
               # Compare the hooks to what is shipped in the repository
               module load EESSI-extend
               diff "$TEMP_FILE" "$EASYBUILD_HOOKS"
-
-        - name: Test that toolchain verification check works
-          if: ${{ github.event_name == 'pull_request' }}
-          run: |
-              # Set up some environment variables
-              export COMPATIBLE_EASYCONFIG=${{matrix.COMPATIBLE_EASYCONFIG}}
-              export INCOMPATIBLE_EASYCONFIG=${{matrix.INCOMPATIBLE_EASYCONFIG}}
-
-              # Load specific EESSI-extend vertsion (proxies a version check)
-              module load EESSI-extend/${{matrix.EESSI_VERSION}}-easybuild
-
-              # Test an easyconfig that should work
-              eb --hooks=$PWD/eb_hooks.py "$COMPATIBLE_EASYCONFIG" --stop fetch
-
-              # Pick an outdated toolchain for the negative test
-              eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch 2>&1 1>/dev/null | grep -q "not supported in EESSI"
-
-              # Check the override works
-              EESSI_OVERRIDE_TOOLCHAIN_CHECK=1 eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch

From 4f5994d04807d179f4ea2178d6ebb617e94c2528 Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Thu, 24 Jul 2025 20:36:34 +0200
Subject: [PATCH 03/14] Separate the checks so that we get a more complete set
 of results

---
 .github/workflows/test-eb-hooks.yml | 76 +++++++++++++++++------------
 1 file changed, 46 insertions(+), 30 deletions(-)

diff --git a/.github/workflows/test-eb-hooks.yml b/.github/workflows/test-eb-hooks.yml
index 9a0a748c..86b225c9 100644
--- a/.github/workflows/test-eb-hooks.yml
+++ b/.github/workflows/test-eb-hooks.yml
@@ -1,5 +1,5 @@
 # documentation: https://help.github.com/en/articles/workflow-syntax-for-github-actions
-name: Check whether eb_hooks.py script is up-to-date
+name: Run checks on EasyBuild hooks script
 on:
   push:
   pull_request:
@@ -7,7 +7,50 @@ on:
 permissions:
   contents: read # to fetch code (actions/checkout)
 jobs:
-  check_eb_hooks:
+  check_eb_hooks_uptodate:
+    runs-on: ubuntu-24.04
+    strategy:
+      matrix:
+        EESSI_VERSION:
+          - '2023.06'
+          - '2025.06'
+
+    steps:
+        - name: Check out software-layer repository
+          uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+
+        - name: Mount EESSI CernVM-FS repository
+          uses: eessi/github-action-eessi@v3
+          with:
+            eessi_stack_version: ${{matrix.EESSI_VERSION}}
+            use_eessi_module: true
+
+        - name: Check whether eb_hooks.py script is up-to-date
+          if: ${{ github.event_name == 'pull_request' }}
+          run: |
+              FILE="eb_hooks.py"
+              TEMP_FILE="$(mktemp)"
+
+              # Fetch base branch
+              git fetch origin ${{ github.base_ref }}
+
+              # Check if the hooks has changed in the PR
+              if git diff --name-only origin/${{ github.base_ref }}...HEAD | grep -q "^$FILE$"; then
+                echo "Hooks 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 > "$TEMP_FILE"
+              fi
+
+              # replace <EESSI_VERSION> placeholder (as is also done in install_scripts.sh)
+              sed -i "s/<EESSI_VERSION>/${{matrix.EESSI_VERSION}}/g" "${TEMP_FILE}"
+
+              # Compare the hooks to what is shipped in the repository
+              module load EESSI-extend
+              diff "$TEMP_FILE" "$EASYBUILD_HOOKS"
+
+  check_eb_hooks_functionality:
     runs-on: ubuntu-24.04
     strategy:
       matrix:
@@ -26,8 +69,6 @@ jobs:
     steps:
         - name: Check out software-layer repository
           uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
-          with:
-              fetch-depth: 0  # Fetch all history for all branches and tags
 
         - name: Mount EESSI CernVM-FS repository
           uses: eessi/github-action-eessi@v3
@@ -35,7 +76,7 @@ jobs:
             eessi_stack_version: ${{matrix.EESSI_VERSION}}
             use_eessi_module: true
 
-        - name: Test that toolchain verification check works
+        - name: Test that hook toolchain verification check works
           if: ${{ github.event_name == 'pull_request' }}
           run: |
               # Set up some environment variables
@@ -53,28 +94,3 @@ jobs:
 
               # Check the override works
               EESSI_OVERRIDE_TOOLCHAIN_CHECK=1 eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch
-
-        - name: Check that EasyBuild hook is up to date
-          if: ${{ github.event_name == 'pull_request' }}
-          run: |
-              FILE="eb_hooks.py"
-              TEMP_FILE="$(mktemp)"
-
-              # Fetch base branch
-              git fetch origin ${{ github.base_ref }}
-
-              # Check if the hooks has changed in the PR
-              if git diff --name-only origin/${{ github.base_ref }}...HEAD | grep -q "^$FILE$"; then
-                echo "Hooks 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 > "$TEMP_FILE"
-              fi
-
-              # replace <EESSI_VERSION> placeholder (as is also done in install_scripts.sh)
-              sed -i "s/<EESSI_VERSION>/${{matrix.EESSI_VERSION}}/g" "${TEMP_FILE}"
-
-              # Compare the hooks to what is shipped in the repository
-              module load EESSI-extend
-              diff "$TEMP_FILE" "$EASYBUILD_HOOKS"

From 4f9802d40273907b4435e85afe65f5a03f7bc3cd Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Thu, 24 Jul 2025 20:44:07 +0200
Subject: [PATCH 04/14] Fix CI checks

---
 .github/workflows/scripts/test_init_scripts.sh | 2 +-
 .github/workflows/test-eb-hooks.yml            | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/scripts/test_init_scripts.sh b/.github/workflows/scripts/test_init_scripts.sh
index 048fba81..bf9abea0 100755
--- a/.github/workflows/scripts/test_init_scripts.sh
+++ b/.github/workflows/scripts/test_init_scripts.sh
@@ -23,7 +23,7 @@ for shell in ${SHELLS[@]}; do
 		echo -e "\033[33mWe don't now how to test the shell '$shell', PRs are Welcome.\033[0m" 
   else
 		# TEST 1: Source Script and check Module Output
-		assert "$shell -c 'source init/lmod/$shell' 2>&1 " "EESSI/$EESSI_VERSION loaded successfully"
+		assert "$shell -c 'source init/lmod/$shell' 2>&1 " "Module for EESSI/$EESSI_VERSION loaded successfully"
 		# TEST 2: Check if module overviews first section is the loaded EESSI module
 		MODULE_SECTIONS=($($shell -c "source init/lmod/$shell 2>/dev/null; module ov 2>&1 | grep -e '---'"))
 		PATTERN="/cvmfs/software\.eessi\.io/versions/$EESSI_VERSION/software/linux/x86_64/(intel/haswell|amd/zen3)/modules/all"
diff --git a/.github/workflows/test-eb-hooks.yml b/.github/workflows/test-eb-hooks.yml
index 86b225c9..8f0420d2 100644
--- a/.github/workflows/test-eb-hooks.yml
+++ b/.github/workflows/test-eb-hooks.yml
@@ -18,7 +18,8 @@ jobs:
     steps:
         - name: Check out software-layer repository
           uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
-
+          with:
+              fetch-depth: 0  # Fetch all history for all branches and tags
         - name: Mount EESSI CernVM-FS repository
           uses: eessi/github-action-eessi@v3
           with:

From e7cf75bf21215e24b58b8965592bba3ab4d7e3b4 Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Fri, 25 Jul 2025 09:13:39 +0200
Subject: [PATCH 05/14] Add capability for site supported toolchains

---
 .github/workflows/test-eb-hooks.yml | 18 ++++++++++++++++++
 eb_hooks.py                         | 21 ++++++++++++++++++++-
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/test-eb-hooks.yml b/.github/workflows/test-eb-hooks.yml
index 8f0420d2..414d65ea 100644
--- a/.github/workflows/test-eb-hooks.yml
+++ b/.github/workflows/test-eb-hooks.yml
@@ -63,9 +63,13 @@ jobs:
           - EESSI_VERSION: '2023.06'
             COMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-13.2.0.eb'
             INCOMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-14.2.0.eb'
+            # Pick a site toolchain that will allow the incompatible easyconfig
+            EESSI_SITE_TOP_LEVEL_TOOLCHAINS: '[{"GCCcore": "14.2.0"}]'
           - EESSI_VERSION: '2025.06'
             COMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-14.2.0.eb'
             INCOMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-13.2.0.eb'
+            # Pick a site toolchain that will allow the incompatible easyconfig
+            EESSI_SITE_TOP_LEVEL_TOOLCHAINS: '[{"GCCcore": "13.2.0"}]'
 
     steps:
         - name: Check out software-layer repository
@@ -89,9 +93,23 @@ jobs:
 
               # Test an easyconfig that should work
               eb --hooks=$PWD/eb_hooks.py "$COMPATIBLE_EASYCONFIG" --stop fetch
+              echo "Success for hook with easyconfig $COMPATIBLE_EASYCONFIG with EESSI/${{matrix.EESSI_VERSION}}"
 
               # Pick an outdated toolchain for the negative test
               eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch 2>&1 1>/dev/null | grep -q "not supported in EESSI"
+              echo "Found expected failure for hook with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
 
               # Check the override works
               EESSI_OVERRIDE_TOOLCHAIN_CHECK=1 eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch
+              echo "Hook ignored via EESSI_OVERRIDE_TOOLCHAIN_CHECK with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
+
+              # Now check if we can set a site list of supported toolchains
+              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS=${{matrix.EESSI_SITE_TOP_LEVEL_TOOLCHAINS}}
+              eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch
+              echo "Site supported toolchain $EESSI_SITE_TOP_LEVEL_TOOLCHAINS successfully used with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
+
+              # Make sure an invalid list of dicts fails
+              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS="Not a list of dicts"
+              eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch 2>&1 1>/dev/null | grep -q "does not contain a valid list of dictionaries"
+              echo "Incorrect format for EESSI_SITE_TOP_LEVEL_TOOLCHAINS caught"
+
diff --git a/eb_hooks.py b/eb_hooks.py
index 97662b41..349c018e 100644
--- a/eb_hooks.py
+++ b/eb_hooks.py
@@ -1,7 +1,9 @@
 # Hooks to customize how EasyBuild installs software in EESSI
 # see https://docs.easybuild.io/en/latest/Hooks.html
+import ast
 import datetime
 import glob
+import json
 import os
 import re
 
@@ -142,10 +144,27 @@ def parse_hook(ec, *args, **kwargs):
     ec = inject_gpu_property(ec)
 
 
+def parse_list_of_dicts_env(var_name):
+    list_string = os.getenv(var_name, '[]')
+    
+    list_of_dicts = []
+    try:
+        # Try JSON format first
+        list_of_dicts = json.loads(list_string)
+    except json.JSONDecodeError:
+        try:
+            # Fall back to Python literal format
+            list_of_dicts = ast.literal_eval(list_string)
+        except (ValueError, SyntaxError):
+            raise ValueError(f"Environment variable '{var_name}' does not contain a valid list of dictionaries.")
+    
+    return list_of_dicts
+
+
 def verify_toolchains_supported_by_eessi_version(easyconfigs):
     """Each EESSI version supports a limited set of toolchains, sanity check the easyconfigs for toolchain support."""
     eessi_version = get_eessi_envvar('EESSI_VERSION')
-    supported_eessi_toolchains = []
+    supported_eessi_toolchains = parse_list_of_dicts_env('EESSI_SITE_TOP_LEVEL_TOOLCHAINS')
     for top_level_toolchain in EESSI_SUPPORTED_TOP_LEVEL_TOOLCHAINS[eessi_version]:
         supported_eessi_toolchains += get_toolchain_hierarchy(top_level_toolchain)
     for ec in easyconfigs:

From 4f11b64a24ab15929314b31dee92f408940360f6 Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Fri, 25 Jul 2025 09:17:23 +0200
Subject: [PATCH 06/14] Be more careful when exporting the variable

---
 .github/workflows/test-eb-hooks.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/test-eb-hooks.yml b/.github/workflows/test-eb-hooks.yml
index 414d65ea..62ee00d5 100644
--- a/.github/workflows/test-eb-hooks.yml
+++ b/.github/workflows/test-eb-hooks.yml
@@ -104,7 +104,7 @@ jobs:
               echo "Hook ignored via EESSI_OVERRIDE_TOOLCHAIN_CHECK with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
 
               # Now check if we can set a site list of supported toolchains
-              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS=${{matrix.EESSI_SITE_TOP_LEVEL_TOOLCHAINS}}
+              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS='${{matrix.EESSI_SITE_TOP_LEVEL_TOOLCHAINS}}'
               eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch
               echo "Site supported toolchain $EESSI_SITE_TOP_LEVEL_TOOLCHAINS successfully used with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
 

From a1cd808c2f7d0c679ce1ea102fe405f1fa2ac059 Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Fri, 25 Jul 2025 09:22:45 +0200
Subject: [PATCH 07/14] One big typo

---
 .github/workflows/test-eb-hooks.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/test-eb-hooks.yml b/.github/workflows/test-eb-hooks.yml
index 62ee00d5..b04f5149 100644
--- a/.github/workflows/test-eb-hooks.yml
+++ b/.github/workflows/test-eb-hooks.yml
@@ -69,7 +69,7 @@ jobs:
             COMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-14.2.0.eb'
             INCOMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-13.2.0.eb'
             # Pick a site toolchain that will allow the incompatible easyconfig
-            EESSI_SITE_TOP_LEVEL_TOOLCHAINS: '[{"GCCcore": "13.2.0"}]'
+            EESSI_SITE_TOP_LEVEL_TOOLCHAINS: '[{"name": "GCCcore", "version": "13.2.0"}]'
 
     steps:
         - name: Check out software-layer repository

From 9957485fb9520dd0618694e134db310760153811 Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Fri, 25 Jul 2025 09:26:59 +0200
Subject: [PATCH 08/14] There were two big typos

---
 .github/workflows/test-eb-hooks.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/test-eb-hooks.yml b/.github/workflows/test-eb-hooks.yml
index b04f5149..0dbd7db1 100644
--- a/.github/workflows/test-eb-hooks.yml
+++ b/.github/workflows/test-eb-hooks.yml
@@ -64,7 +64,7 @@ jobs:
             COMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-13.2.0.eb'
             INCOMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-14.2.0.eb'
             # Pick a site toolchain that will allow the incompatible easyconfig
-            EESSI_SITE_TOP_LEVEL_TOOLCHAINS: '[{"GCCcore": "14.2.0"}]'
+            EESSI_SITE_TOP_LEVEL_TOOLCHAINS: '[{"name": "GCCcore", "version": "14.2.0"}]'
           - EESSI_VERSION: '2025.06'
             COMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-14.2.0.eb'
             INCOMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-13.2.0.eb'

From 541b40aed8818fa588465f3a9ae6b27ea1cc8b87 Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Fri, 25 Jul 2025 09:42:09 +0200
Subject: [PATCH 09/14] Allow there to be an environment variable per EESSI
 version for site top-level toolchains

---
 .github/workflows/test-eb-hooks.yml | 4 ++--
 eb_hooks.py                         | 5 +++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/test-eb-hooks.yml b/.github/workflows/test-eb-hooks.yml
index 0dbd7db1..362e6363 100644
--- a/.github/workflows/test-eb-hooks.yml
+++ b/.github/workflows/test-eb-hooks.yml
@@ -104,12 +104,12 @@ jobs:
               echo "Hook ignored via EESSI_OVERRIDE_TOOLCHAIN_CHECK with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
 
               # Now check if we can set a site list of supported toolchains
-              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS='${{matrix.EESSI_SITE_TOP_LEVEL_TOOLCHAINS}}'
+              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS_"${{matrix.EESSI_VERSION}}"='${{matrix.EESSI_SITE_TOP_LEVEL_TOOLCHAINS}}'
               eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch
               echo "Site supported toolchain $EESSI_SITE_TOP_LEVEL_TOOLCHAINS successfully used with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
 
               # Make sure an invalid list of dicts fails
-              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS="Not a list of dicts"
+              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS_"${{matrix.EESSI_VERSION}}"="Not a list of dicts"
               eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch 2>&1 1>/dev/null | grep -q "does not contain a valid list of dictionaries"
               echo "Incorrect format for EESSI_SITE_TOP_LEVEL_TOOLCHAINS caught"
 
diff --git a/eb_hooks.py b/eb_hooks.py
index 349c018e..2bf2a381 100644
--- a/eb_hooks.py
+++ b/eb_hooks.py
@@ -164,8 +164,9 @@ def parse_list_of_dicts_env(var_name):
 def verify_toolchains_supported_by_eessi_version(easyconfigs):
     """Each EESSI version supports a limited set of toolchains, sanity check the easyconfigs for toolchain support."""
     eessi_version = get_eessi_envvar('EESSI_VERSION')
-    supported_eessi_toolchains = parse_list_of_dicts_env('EESSI_SITE_TOP_LEVEL_TOOLCHAINS')
-    for top_level_toolchain in EESSI_SUPPORTED_TOP_LEVEL_TOOLCHAINS[eessi_version]:
+    supported_eessi_toolchains = []
+    site_top_level_toolchains = parse_list_of_dicts_env('EESSI_SITE_TOP_LEVEL_TOOLCHAINS_' + eessi_version)
+    for top_level_toolchain in EESSI_SUPPORTED_TOP_LEVEL_TOOLCHAINS[eessi_version] + site_top_level_toolchains:
         supported_eessi_toolchains += get_toolchain_hierarchy(top_level_toolchain)
     for ec in easyconfigs:
         toolchain = ec['ec']['toolchain']

From ef953f58ec19a26c4038d79984434d6911a13fd2 Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Fri, 25 Jul 2025 09:53:07 +0200
Subject: [PATCH 10/14] Make sure expected envvars have valid syntax

---
 .github/workflows/test-eb-hooks.yml | 11 +++++++----
 eb_hooks.py                         |  4 +++-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/test-eb-hooks.yml b/.github/workflows/test-eb-hooks.yml
index 362e6363..1020b323 100644
--- a/.github/workflows/test-eb-hooks.yml
+++ b/.github/workflows/test-eb-hooks.yml
@@ -64,12 +64,14 @@ jobs:
             COMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-13.2.0.eb'
             INCOMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-14.2.0.eb'
             # Pick a site toolchain that will allow the incompatible easyconfig
-            EESSI_SITE_TOP_LEVEL_TOOLCHAINS: '[{"name": "GCCcore", "version": "14.2.0"}]'
+            # (the name will be modified when exported)
+            SITE_TOP_LEVEL_TOOLCHAINS: '[{"name": "GCCcore", "version": "14.2.0"}]'
           - EESSI_VERSION: '2025.06'
             COMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-14.2.0.eb'
             INCOMPATIBLE_EASYCONFIG: 'M4-1.4.19-GCCcore-13.2.0.eb'
             # Pick a site toolchain that will allow the incompatible easyconfig
-            EESSI_SITE_TOP_LEVEL_TOOLCHAINS: '[{"name": "GCCcore", "version": "13.2.0"}]'
+            # (the name will be modified when exported)
+            SITE_TOP_LEVEL_TOOLCHAINS: '[{"name": "GCCcore", "version": "13.2.0"}]'
 
     steps:
         - name: Check out software-layer repository
@@ -104,12 +106,13 @@ jobs:
               echo "Hook ignored via EESSI_OVERRIDE_TOOLCHAIN_CHECK with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
 
               # Now check if we can set a site list of supported toolchains
-              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS_"${{matrix.EESSI_VERSION}}"='${{matrix.EESSI_SITE_TOP_LEVEL_TOOLCHAINS}}'
+              export SANITIZED_EESSI_VERSION=$(echo "${{ matrix.EESSI_VERSION }}" | sed 's/\./_/g')
+              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS_"$SANITIZED_EESSI_VERSION"='${{matrix.SITE_TOP_LEVEL_TOOLCHAINS}}'
               eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch
               echo "Site supported toolchain $EESSI_SITE_TOP_LEVEL_TOOLCHAINS successfully used with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
 
               # Make sure an invalid list of dicts fails
-              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS_"${{matrix.EESSI_VERSION}}"="Not a list of dicts"
+              export EESSI_SITE_TOP_LEVEL_TOOLCHAINS_"$SANITIZED_EESSI_VERSION"="Not a list of dicts"
               eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch 2>&1 1>/dev/null | grep -q "does not contain a valid list of dictionaries"
               echo "Incorrect format for EESSI_SITE_TOP_LEVEL_TOOLCHAINS caught"
 
diff --git a/eb_hooks.py b/eb_hooks.py
index 2bf2a381..3525a81e 100644
--- a/eb_hooks.py
+++ b/eb_hooks.py
@@ -165,7 +165,9 @@ def verify_toolchains_supported_by_eessi_version(easyconfigs):
     """Each EESSI version supports a limited set of toolchains, sanity check the easyconfigs for toolchain support."""
     eessi_version = get_eessi_envvar('EESSI_VERSION')
     supported_eessi_toolchains = []
-    site_top_level_toolchains = parse_list_of_dicts_env('EESSI_SITE_TOP_LEVEL_TOOLCHAINS_' + eessi_version)
+    # Environment variable can't have a '.' so replace by '_'
+    site_top_level_toolchains_envvar = 'EESSI_SITE_TOP_LEVEL_TOOLCHAINS_' + eessi_version.replace('.', '_')
+    site_top_level_toolchains = parse_list_of_dicts_env(site_top_level_toolchains_envvar)
     for top_level_toolchain in EESSI_SUPPORTED_TOP_LEVEL_TOOLCHAINS[eessi_version] + site_top_level_toolchains:
         supported_eessi_toolchains += get_toolchain_hierarchy(top_level_toolchain)
     for ec in easyconfigs:

From bfe97777e291a1943309dbb76320c0b66d3f8b00 Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Fri, 25 Jul 2025 09:55:11 +0200
Subject: [PATCH 11/14] Add a check to verify the name of the environment
 variable

---
 eb_hooks.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/eb_hooks.py b/eb_hooks.py
index 3525a81e..034272ce 100644
--- a/eb_hooks.py
+++ b/eb_hooks.py
@@ -145,6 +145,11 @@ def parse_hook(ec, *args, **kwargs):
 
 
 def parse_list_of_dicts_env(var_name):
+    """Parse a list of dicts that are stored in an environment variable string"""
+
+    # Check if the environment variable name is valid (letters, numbers, underscores, and doesn't start with a digit)
+    if not re.match(r'^[A-Za-z_][A-Za-z0-9_]*$', var_name):
+        raise ValueError(f"Invalid environment variable name: {var_name}")
     list_string = os.getenv(var_name, '[]')
     
     list_of_dicts = []

From 3c1c429f2887abf68f38f4c5f0921318512b9b61 Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Fri, 25 Jul 2025 10:07:03 +0200
Subject: [PATCH 12/14] Update some CI comments

---
 .github/workflows/test-eb-hooks.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/test-eb-hooks.yml b/.github/workflows/test-eb-hooks.yml
index 1020b323..416cd99c 100644
--- a/.github/workflows/test-eb-hooks.yml
+++ b/.github/workflows/test-eb-hooks.yml
@@ -97,7 +97,7 @@ jobs:
               eb --hooks=$PWD/eb_hooks.py "$COMPATIBLE_EASYCONFIG" --stop fetch
               echo "Success for hook with easyconfig $COMPATIBLE_EASYCONFIG with EESSI/${{matrix.EESSI_VERSION}}"
 
-              # Pick an outdated toolchain for the negative test
+              # Now ensure an incompatible easyconfig does not work
               eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch 2>&1 1>/dev/null | grep -q "not supported in EESSI"
               echo "Found expected failure for hook with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
 
@@ -109,7 +109,7 @@ jobs:
               export SANITIZED_EESSI_VERSION=$(echo "${{ matrix.EESSI_VERSION }}" | sed 's/\./_/g')
               export EESSI_SITE_TOP_LEVEL_TOOLCHAINS_"$SANITIZED_EESSI_VERSION"='${{matrix.SITE_TOP_LEVEL_TOOLCHAINS}}'
               eb --hooks=$PWD/eb_hooks.py "$INCOMPATIBLE_EASYCONFIG" --stop fetch
-              echo "Site supported toolchain $EESSI_SITE_TOP_LEVEL_TOOLCHAINS successfully used with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
+              echo "Site supported toolchain from $EESSI_SITE_TOP_LEVEL_TOOLCHAINS successfully used with easyconfig $INCOMPATIBLE_EASYCONFIG and EESSI/${{matrix.EESSI_VERSION}}"
 
               # Make sure an invalid list of dicts fails
               export EESSI_SITE_TOP_LEVEL_TOOLCHAINS_"$SANITIZED_EESSI_VERSION"="Not a list of dicts"

From ef560294ff6e231599f2f48fdda279007960ed04 Mon Sep 17 00:00:00 2001
From: ocaisa <alan.ocais@cecam.org>
Date: Fri, 25 Jul 2025 10:09:41 +0200
Subject: [PATCH 13/14] Update eb_hooks.py

---
 eb_hooks.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/eb_hooks.py b/eb_hooks.py
index 034272ce..41895eb5 100644
--- a/eb_hooks.py
+++ b/eb_hooks.py
@@ -240,7 +240,7 @@ def post_ready_hook(self, *args, **kwargs):
     # apply the limit if it's different from current
     if new_parallel != parallel:
         if hasattr(self, 'parallel'):
-            self.parallel = new_parallel
+            self.cfg.parallel = new_parallel
         else:
             self.cfg['parallel'] = new_parallel
         msg = "limiting parallelism to %s (was %s) for %s on %s to avoid out-of-memory failures during building/testing"

From 9dabe2cecd0eef6dfdf0306fefb4766b41609590 Mon Sep 17 00:00:00 2001
From: Alan O'Cais <alan.ocais@cecam.org>
Date: Fri, 25 Jul 2025 10:51:31 +0200
Subject: [PATCH 14/14] Add a comment for strange looking dict comparison

---
 eb_hooks.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/eb_hooks.py b/eb_hooks.py
index 41895eb5..bdf8f49b 100644
--- a/eb_hooks.py
+++ b/eb_hooks.py
@@ -180,6 +180,9 @@ def verify_toolchains_supported_by_eessi_version(easyconfigs):
         # if it is a system toolchain or appears in the list, we are all good
         if is_system_toolchain(toolchain['name']):
             continue
+        # This check verifies that the toolchain dict is in the list of supported toolchains.
+        # It uses <= as there may be other dict entries in the values returned from get_toolchain_hierarchy()
+        # but we only care that the toolchain dict (which has 'name' and 'version') appear.
         elif not any(toolchain.items() <= supported.items() for supported in supported_eessi_toolchains):
             raise EasyBuildError(
                 f"Toolchain {toolchain} (required by {ec['full_mod_name']}) is not supported in EESSI/{eessi_version}\n"