EESSI · ocaisa · Jan 28, 2026 · Jan 28, 2026 · Jan 28, 2026 · Jan 28, 2026
diff --git a/.github/workflows/modules/append_module.lua b/.github/workflows/modules/append_module.lua
@@ -0,0 +1,3 @@
+setenv("INSIDE_GITHUB_ACTIONS", "true")
+-- Interfere with PATH so Lmod keeps a record
+prepend_path("PATH", "/snap/bin")
diff --git a/.github/workflows/modules/prepend_module.lua b/.github/workflows/modules/prepend_module.lua
@@ -0,0 +1,3 @@
+setenv("INSIDE_GITHUB_ACTIONS", "true")
+-- Interfere with PATH so Lmod keeps a record
+prepend_path("PATH", "/snap/bin")
diff --git a/.github/workflows/scripts/test_init_scripts.sh b/.github/workflows/scripts/test_init_scripts.sh
@@ -45,11 +45,12 @@ for shell in ${SHELLS[@]}; do
     else
       MODULE_SECTIONS=($($shell -c "source init/lmod/$shell 2>/dev/null; module ov 2>&1 | grep -e '---'"))
     fi
-    PATTERN="/cvmfs/software\.eessi\.io/versions/$EESSI_VERSION/software/linux/x86_64/(intel/haswell|amd/zen3)/modules/all"
+    PATTERN="/cvmfs/software\.eessi\.io/versions/$EESSI_VERSION/software/linux/x86_64/(intel/haswell|amd/zen3|intel/icelake)/modules/all"
     assert_raises 'echo "${MODULE_SECTIONS[1]}" | grep -E "$PATTERN"'
+    echo "${MODULE_SECTIONS[1]}" "$PATTERN"
 
     # TEST 3: Check if module overviews second section is the EESSI init module
-    assert "echo ${MODULE_SECTIONS[4]}" "/cvmfs/software.eessi.io/versions/$EESSI_VERSION/init/modules"
+    assert "echo ${MODULE_SECTIONS[4]}" "/cvmfs/software.eessi.io/init/modules"
 
     # TEST 4: Load EasyBuild module and check version
     # eb --version outputs: "This is EasyBuild 5.1.1 (framework: 5.1.1, easyblocks: 5.1.1) on host ..."
@@ -69,9 +70,37 @@ for shell in ${SHELLS[@]}; do
       EASYBUILD_PATH=$($shell -c "source init/lmod/$shell 2>/dev/null; module load EasyBuild/${EXPECTED_EASYBUILD_VERSION}; which eb")
     fi
     # escape the dots in ${EASYBUILD_VERSION}
-    PATTERN="/cvmfs/software\.eessi\.io/versions/$EESSI_VERSION/software/linux/x86_64/(intel/haswell|amd/zen3)/software/EasyBuild/${EXPECTED_EASYBUILD_VERSION//./\\.}/bin/eb"
+    PATTERN="/cvmfs/software\.eessi\.io/versions/$EESSI_VERSION/software/linux/x86_64/(intel/haswell|amd/zen3|intel/icelake)/software/EasyBuild/${EXPECTED_EASYBUILD_VERSION//./\\.}/bin/eb"
     echo "$EASYBUILD_PATH" | grep -E "$PATTERN"
     assert_raises 'echo "$EASYBUILD_PATH" | grep -E "$PATTERN"'
+    echo "$EASYBUILD_PATH" "$PATTERN"
+
+    # TEST 6 and 7: Check the various options (EESSI_DEFAULT_MODULES_APPEND, EESSI_DEFAULT_MODULES_APPEND, EESSI_EXTRA_MODULEPATH) all work
+    if [ "$shell" = "csh" ]; then
+      echo "setenv EESSI_DEFAULT_MODULES_APPEND append_module" > ~/.cshrc
+      echo "setenv EESSI_DEFAULT_MODULES_PREPEND prepend_module" >> ~/.cshrc
+      echo "setenv EESSI_EXTRA_MODULEPATH .github/workflows/modules" >> ~/.cshrc
+      echo "source init/lmod/$shell" >> ~/.cshrc
+      TEST_LMOD_SYSTEM_DEFAULT_MODULES=$($shell -c 'echo $LMOD_SYSTEM_DEFAULT_MODULES')
+      TEST_MODULEPATH=$($shell -c 'echo $MODULEPATH')
+    elif [ "$shell" = "fish" ]; then
+      TEST_LMOD_SYSTEM_DEFAULT_MODULES=$($shell -c 'set -x EESSI_DEFAULT_MODULES_APPEND append_module ; set -x EESSI_DEFAULT_MODULES_PREPEND prepend_module ; set -x EESSI_EXTRA_MODULEPATH .github/workflows/modules ; source init/lmod/'"$shell"' 2>/dev/null; echo $LMOD_SYSTEM_DEFAULT_MODULES')
+      TEST_MODULEPATH=$($shell -c 'set -x EESSI_DEFAULT_MODULES_APPEND append_module ; set -x EESSI_DEFAULT_MODULES_PREPEND prepend_module ; set -x EESSI_EXTRA_MODULEPATH .github/workflows/modules ; source init/lmod/'"$shell"' 2>/dev/null; echo $MODULEPATH')
+    else
+      TEST_LMOD_SYSTEM_DEFAULT_MODULES=$($shell -c 'export EESSI_DEFAULT_MODULES_APPEND=append_module ; export EESSI_DEFAULT_MODULES_PREPEND=prepend_module ; export EESSI_EXTRA_MODULEPATH=.github/workflows/modules ; source init/lmod/'"$shell"' ; echo $LMOD_SYSTEM_DEFAULT_MODULES')
+      TEST_MODULEPATH=$($shell -c 'export EESSI_DEFAULT_MODULES_APPEND=append_module ; export EESSI_DEFAULT_MODULES_PREPEND=prepend_module ; export EESSI_EXTRA_MODULEPATH=.github/workflows/modules ; source init/lmod/'"$shell"' 2>/dev/null; echo $MODULEPATH')
+    fi
+    # escape the dots in ${EASYBUILD_VERSION}
+    LMOD_SYSTEM_DEFAULT_MODULES_PATTERN='^prepend_module:.*:append_module$'
+    echo "$TEST_LMOD_SYSTEM_DEFAULT_MODULES" AND "$LMOD_SYSTEM_DEFAULT_MODULES_PATTERN"
+    assert_raises 'echo "$TEST_LMOD_SYSTEM_DEFAULT_MODULES" | grep -E "$LMOD_SYSTEM_DEFAULT_MODULES_PATTERN"'
+    if [ "$shell" = "fish" ]; then
+      MODULEPATH_PATTERN='\.github/workflows/modules$'
+    else
+      MODULEPATH_PATTERN=':\.github/workflows/modules$'
+    fi
+    echo "$TEST_MODULEPATH" AND "$MODULEPATH_PATTERN"
+    assert_raises 'echo "$TEST_MODULEPATH" | grep -E "$MODULEPATH_PATTERN"'
 
     # End Test Suite
     assert_end "source_eessi_$shell"

diff --git a/.github/workflows/tests_init_module.yml b/.github/workflows/tests_init_module.yml
@@ -57,6 +57,7 @@ jobs:
 
       - name: Run tests for available shells
         run: |
+          export EESSI_SOFTWARE_SUBDIR_OVERRIDE=${{matrix.EESSI_SOFTWARE_SUBDIR_OVERRIDE}}
           export EESSI_VERSION=${{matrix.EESSI_VERSION}}
           export EXPECTED_EASYBUILD_VERSION=${{matrix.EXPECTED_EASYBUILD_VERSION}}
           .github/workflows/scripts/test_init_scripts.sh "bash" "zsh" "ksh" "fish" "csh"

diff --git a/init/lmod/bash b/init/lmod/bash
@@ -3,17 +3,28 @@ EESSI_CVMFS_REPO="${EESSI_CVMFS_REPO:-/cvmfs/software.eessi.io}"
 # Choose an EESSI version
 EESSI_VERSION_DEFAULT="__EESSI_VERSION_DEFAULT__"
 EESSI_VERSION="${EESSI_VERSION:-${EESSI_VERSION_DEFAULT}}"
-# Path to top-level module tree
-export MODULEPATH="${EESSI_CVMFS_REPO}/versions/${EESSI_VERSION}/init/modules"
-. "${EESSI_CVMFS_REPO}/versions/${EESSI_VERSION}/compat/linux/$(uname -m)/usr/share/Lmod/init/bash"
+# Now that we know our EESSI version let's not forget it
+export EESSI_VERSION_DEFAULT="$EESSI_VERSION"
 
-if [ -z "$__Init_Default_Modules" ]; then
-   export __Init_Default_Modules=1;
+# ability to predefine elsewhere the default list (with options to append or prepend)
+LMOD_SYSTEM_DEFAULT_MODULES="${EESSI_DEFAULT_MODULES_PREPEND:+$EESSI_DEFAULT_MODULES_PREPEND:}EESSI/$EESSI_VERSION${EESSI_DEFAULT_MODULES_APPEND:+:$EESSI_DEFAULT_MODULES_APPEND}"
+export LMOD_SYSTEM_DEFAULT_MODULES
 
-   ## ability to predefine elsewhere the default list
-   LMOD_SYSTEM_DEFAULT_MODULES=${LMOD_SYSTEM_DEFAULT_MODULES:-"EESSI/$EESSI_VERSION"}
-   export LMOD_SYSTEM_DEFAULT_MODULES
-   module --initial_load --no_redirect restore
+if [ -z "$__Init_EESSI_Default_Modules" ]; then
+    export __Init_EESSI_Default_Modules=1;
+
+    # Lmod version in 2023.06 has a problem with newer Lmod caches, so let's stick to more recent Lmod
+    # (has no effect except on Lmod itself, and compatible caches are still created/supported by EESSI)
+    LMOD_EESSI_VERSION=${EESSI_VERSION/2023.06/2025.06}
+
+    # If there is a local Lmod, make it forget about the system set MODULEPATH
+    unset __LMOD_REF_COUNT_MODULEPATH
+    # and clear out any memory Lmod might have
+    unset _ModuleTable001_
+    # Path to top-level module tree
+    export MODULEPATH="${EESSI_CVMFS_REPO}/init/modules${EESSI_EXTRA_MODULEPATH:+:$EESSI_EXTRA_MODULEPATH}"
+    . "${EESSI_CVMFS_REPO}/versions/${LMOD_EESSI_VERSION}/compat/linux/$(uname -m)/usr/share/Lmod/init/bash"
+    module --initial_load --no_redirect restore
 else
-   module refresh
+    module reset
 fi
diff --git a/init/lmod/csh b/init/lmod/csh
@@ -1,24 +1,51 @@
 # Choose an EESSI CVMFS repository
-if (! $?EESSI_CVMFS_REPO) then
+if ( ! $?EESSI_CVMFS_REPO) then
     set EESSI_CVMFS_REPO = "/cvmfs/software.eessi.io"
 endif
 # Choose an EESSI version
 setenv EESSI_VERSION_DEFAULT "__EESSI_VERSION_DEFAULT__"
-if (! $?EESSI_VERSION) then
+if ( ! $?EESSI_VERSION) then
     set EESSI_VERSION = "${EESSI_VERSION_DEFAULT}"
 endif
-# Path to top-level module tree
-setenv MODULEPATH "${EESSI_CVMFS_REPO}/versions/${EESSI_VERSION}/init/modules"
-source "${EESSI_CVMFS_REPO}/versions/${EESSI_VERSION}/compat/linux/`uname -m`/usr/share/Lmod/init/csh"
+# Now that we know our EESSI version let's not forget it
+setenv EESSI_VERSION_DEFAULT "${EESSI_VERSION}"
 
-if (! $?__Init_Default_Modules ) then
-    setenv __Init_Default_Modules 1
+# ability to predefine elsewhere the default list (with options to append or prepend)
+set LMOD_SYSTEM_DEFAULT_MODULES="EESSI/${EESSI_VERSION}"
+if ( $?EESSI_DEFAULT_MODULES_PREPEND ) then
+    set LMOD_SYSTEM_DEFAULT_MODULES="${EESSI_DEFAULT_MODULES_PREPEND}:${LMOD_SYSTEM_DEFAULT_MODULES}"
+endif
+if ( $?EESSI_DEFAULT_MODULES_APPEND ) then
+    set LMOD_SYSTEM_DEFAULT_MODULES="${LMOD_SYSTEM_DEFAULT_MODULES}:${EESSI_DEFAULT_MODULES_APPEND}"
+endif
+setenv LMOD_SYSTEM_DEFAULT_MODULES "${LMOD_SYSTEM_DEFAULT_MODULES}"
+
+if ( ! $?__Init_EESSI_Default_Modules ) then
+    setenv __Init_EESSI_Default_Modules 1
 
-    # ability to predefine elsewhere the default list
-    if (! $?LMOD_SYSTEM_DEFAULT_MODULES) then
-        setenv LMOD_SYSTEM_DEFAULT_MODULES "EESSI/${EESSI_VERSION}"
+    # Lmod version in 2023.06 has a problem with newer Lmod caches, so let's stick to more recent Lmod
+    # (has no effect except on Lmod itself, and compatible caches are still created/supported by EESSI)
+    set LMOD_EESSI_VERSION="${EESSI_VERSION}"
+    if ( "${LMOD_EESSI_VERSION}" == "2023.06" ) then
+      set LMOD_EESSI_VERSION="2025.06"
     endif
+
+    # If there is a local Lmod, make it forget about the system set MODULEPATH
+    unsetenv __LMOD_REF_COUNT_MODULEPATH
+    # and clear out any memory Lmod might have
+    unsetenv _ModuleTable001_
+    # Path to top-level module tree
+    set modulepath="${EESSI_CVMFS_REPO}/init/modules"
+    if ( $?EESSI_EXTRA_MODULEPATH ) then
+      # Now that we know it exists, check IF it is not empty
+      if ( "$EESSI_EXTRA_MODULEPATH" != "" ) then
+        set modulepath="${modulepath}:${EESSI_EXTRA_MODULEPATH}"
+      endif
+    endif
+    setenv MODULEPATH "$modulepath"
+    source "${EESSI_CVMFS_REPO}/versions/${LMOD_EESSI_VERSION}/compat/linux/`uname -m`/usr/share/Lmod/init/csh"
+
     module --initial_load --no_redirect restore
 else
-    module refresh
+    module reset
 endif
diff --git a/init/lmod/fish b/init/lmod/fish
@@ -3,16 +3,39 @@ set EESSI_CVMFS_REPO (set -q EESSI_CVMFS_REPO; and echo "$EESSI_CVMFS_REPO"; or
 # Choose an EESSI version
 set EESSI_VERSION_DEFAULT "__EESSI_VERSION_DEFAULT__"
 set EESSI_VERSION (set -q EESSI_VERSION; and echo "$EESSI_VERSION"; or echo "$EESSI_VERSION_DEFAULT")
-# Path to top-level module tree
-set -x MODULEPATH "$EESSI_CVMFS_REPO"/versions/"$EESSI_VERSION"/init/modules
-. "$EESSI_CVMFS_REPO"/versions/"$EESSI_VERSION"/compat/linux/(uname -m)/usr/share/Lmod/init/fish
+# Now that we know our EESSI version let's not forget it
+set -x EESSI_VERSION_DEFAULT "$EESSI_VERSION"
 
-if test -z "$__Init_Default_Modules"
-	export __Init_Default_Modules=1;
+# ability to predefine elsewhere the default list (with options to append or prepend)
+set LMOD_SYSTEM_DEFAULT_MODULES "EESSI/$EESSI_VERSION"
+if set -q EESSI_DEFAULT_MODULES_PREPEND
+    set LMOD_SYSTEM_DEFAULT_MODULES "$EESSI_DEFAULT_MODULES_PREPEND:$LMOD_SYSTEM_DEFAULT_MODULES"
+end
+if set -q EESSI_DEFAULT_MODULES_APPEND
+    set LMOD_SYSTEM_DEFAULT_MODULES "$LMOD_SYSTEM_DEFAULT_MODULES:$EESSI_DEFAULT_MODULES_APPEND"
+end
+set -x LMOD_SYSTEM_DEFAULT_MODULES $LMOD_SYSTEM_DEFAULT_MODULES
+
+if test -z "$__Init_EESSI_Default_Modules"
+    set -x __Init_EESSI_Default_Modules 1
+
+    # Lmod version in 2023.06 has a problem with newer Lmod caches, so let's stick to more recent Lmod
+    # (has no effect except on Lmod itself, and compatible caches are still created/supported by EESSI)
+    set LMOD_EESSI_VERSION (string replace 2023.06 2025.06 -- $EESSI_VERSION)
+
+    # If there is a local Lmod, make it forget about the system set MODULEPATH
+    set -e __LMOD_REF_COUNT_MODULEPATH
+    # and clear out any memory Lmod might have
+    set -e _ModuleTable001_
+    # Path to top-level module tree
+    set modulepath "$EESSI_CVMFS_REPO/init/modules"
+    if set -q EESSI_EXTRA_MODULEPATH; and test -n "$EESSI_EXTRA_MODULEPATH"
+        set modulepath "$modulepath:$EESSI_EXTRA_MODULEPATH"
+    end
+    set -x MODULEPATH $modulepath
+    . "$EESSI_CVMFS_REPO"/versions/"$LMOD_EESSI_VERSION"/compat/linux/(uname -m)/usr/share/Lmod/init/fish
 
-	## ability to predefine elsewhere the default list
-	set -x LMOD_SYSTEM_DEFAULT_MODULES (set -q LMOD_SYSTEM_DEFAULT_MODULE; and echo "$LMOD_SYSTEM_DEFAULT_MODULE"; or echo "EESSI/$EESSI_VERSION")
-	module --initial_load --no_redirect restore
+    module --initial_load --no_redirect restore
 else
-	module refresh
+    module reset
 end
diff --git a/init/lmod/ksh b/init/lmod/ksh
@@ -3,17 +3,29 @@ EESSI_CVMFS_REPO="${EESSI_CVMFS_REPO:-/cvmfs/software.eessi.io}"
 # Choose an EESSI version
 EESSI_VERSION_DEFAULT="__EESSI_VERSION_DEFAULT__"
 EESSI_VERSION="${EESSI_VERSION:-${EESSI_VERSION_DEFAULT}}"
-# Path to top-level module tree
-export MODULEPATH="${EESSI_CVMFS_REPO}/versions/${EESSI_VERSION}/init/modules"
-. "${EESSI_CVMFS_REPO}/versions/${EESSI_VERSION}/compat/linux/$(uname -m)/usr/share/Lmod/init/ksh"
+# Now that we know our EESSI version let's not forget it
+export EESSI_VERSION_DEFAULT="$EESSI_VERSION"
 
-if [ -z "$__Init_Default_Modules" ]; then
-   export __Init_Default_Modules=1;
+# ability to predefine elsewhere the default list (with options to append or prepend)
+LMOD_SYSTEM_DEFAULT_MODULES="${EESSI_DEFAULT_MODULES_PREPEND:+$EESSI_DEFAULT_MODULES_PREPEND:}EESSI/$EESSI_VERSION${EESSI_DEFAULT_MODULES_APPEND:+:$EESSI_DEFAULT_MODULES_APPEND}"
+export LMOD_SYSTEM_DEFAULT_MODULES
+
+if [ -z "$__Init_EESSI_Default_Modules" ]; then
+    export __Init_EESSI_Default_Modules=1;
 
-   ## ability to predefine elsewhere the default list
-   LMOD_SYSTEM_DEFAULT_MODULES=${LMOD_SYSTEM_DEFAULT_MODULES:-"EESSI/$EESSI_VERSION"}
-   export LMOD_SYSTEM_DEFAULT_MODULES
-   module --initial_load --no_redirect restore
+    # Lmod version in 2023.06 has a problem with newer Lmod caches, so let's stick to more recent Lmod
+    # (has no effect except on Lmod itself, and compatible caches are still created/supported by EESSI)
+    LMOD_EESSI_VERSION=${EESSI_VERSION/2023.06/2025.06}
+
+    # If there is a local Lmod, make it forget about the system set MODULEPATH
+    unset __LMOD_REF_COUNT_MODULEPATH
+    # and clear out any memory Lmod might have
+    unset _ModuleTable001_
+    # Path to top-level module tree
+    export MODULEPATH="${EESSI_CVMFS_REPO}/init/modules${EESSI_EXTRA_MODULEPATH:+:$EESSI_EXTRA_MODULEPATH}"
+    . "${EESSI_CVMFS_REPO}/versions/${LMOD_EESSI_VERSION}/compat/linux/$(uname -m)/usr/share/Lmod/init/ksh"
+
+    module --initial_load --no_redirect restore
 else
-   module refresh
+    module reset
 fi
diff --git a/init/lmod/zsh b/init/lmod/zsh
@@ -3,17 +3,29 @@ EESSI_CVMFS_REPO="${EESSI_CVMFS_REPO:-/cvmfs/software.eessi.io}"
 # Choose an EESSI version
 EESSI_VERSION_DEFAULT="__EESSI_VERSION_DEFAULT__"
 EESSI_VERSION="${EESSI_VERSION:-${EESSI_VERSION_DEFAULT}}"
-# Path to top-level module tree
-export MODULEPATH="${EESSI_CVMFS_REPO}/versions/${EESSI_VERSION}/init/modules"
-. "${EESSI_CVMFS_REPO}/versions/${EESSI_VERSION}/compat/linux/$(uname -m)/usr/share/Lmod/init/zsh"
+# Now that we know our EESSI version let's not forget it
+export EESSI_VERSION_DEFAULT="$EESSI_VERSION"
 
-if [ -z "$__Init_Default_Modules" ]; then
-   export __Init_Default_Modules=1;
+# ability to predefine elsewhere the default list (with options to append or prepend)
+LMOD_SYSTEM_DEFAULT_MODULES="${EESSI_DEFAULT_MODULES_PREPEND:+$EESSI_DEFAULT_MODULES_PREPEND:}EESSI/$EESSI_VERSION${EESSI_DEFAULT_MODULES_APPEND:+:$EESSI_DEFAULT_MODULES_APPEND}"
+export LMOD_SYSTEM_DEFAULT_MODULES
 
-   ## ability to predefine elsewhere the default list
-   LMOD_SYSTEM_DEFAULT_MODULES=${LMOD_SYSTEM_DEFAULT_MODULES:-"EESSI/$EESSI_VERSION"}
-   export LMOD_SYSTEM_DEFAULT_MODULES
-   module --initial_load --no_redirect restore
+if [ -z "$__Init_EESSI_Default_Modules" ]; then
+    export __Init_EESSI_Default_Modules=1;
+
+    # Lmod version in 2023.06 has a problem with newer Lmod caches, so let's stick to more recent Lmod
+    # (has no effect except on Lmod itself, and compatible caches are still created/supported by EESSI)
+    LMOD_EESSI_VERSION=${EESSI_VERSION/2023.06/2025.06}
+
+    # If there is a local Lmod, make it forget about the system set MODULEPATH
+    unset __LMOD_REF_COUNT_MODULEPATH
+    # and clear out any memory Lmod might have
+    unset _ModuleTable001_
+    # Path to top-level module tree
+    export MODULEPATH="${EESSI_CVMFS_REPO}/init/modules${EESSI_EXTRA_MODULEPATH:+:$EESSI_EXTRA_MODULEPATH}"
+    . "${EESSI_CVMFS_REPO}/versions/${LMOD_EESSI_VERSION}/compat/linux/$(uname -m)/usr/share/Lmod/init/zsh"
+
+    module --initial_load --no_redirect restore
 else
-   module refresh
+    module reset
 fi