diff --git a/.github/workflows/tests_archdetect.yml b/.github/workflows/tests_archdetect.yml
index 618f6eb142..74dbf032f0 100644
--- a/.github/workflows/tests_archdetect.yml
+++ b/.github/workflows/tests_archdetect.yml
@@ -13,24 +13,59 @@ jobs:
           - x86_64/intel/skylake_avx512/archspec-linux-6132
           - x86_64/amd/zen2/Azure-CentOS7-7V12
           - x86_64/amd/zen3/Azure-CentOS7-7V73X
-          - ppc64le/power9le/unknown-power9le
-          - aarch64/arm/neoverse-n1/Azure-Ubuntu20-Altra
-          - aarch64/arm/neoverse-n1/AWS-awslinux-graviton2
-          - aarch64/arm/neoverse-v1/AWS-awslinux-graviton3
+          # commented out since these targets are currently not supported in pilot.nessi.no repo
+          # (and some tests assume that the corresponding subdirectory in software layer is there)
+          # - ppc64le/power9le/unknown-power9le
+          # - aarch64/neoverse-n1/Azure-Ubuntu20-Altra
+          # - aarch64/neoverse-n1/AWS-awslinux-graviton2
+          # - aarch64/neoverse-v1/AWS-awslinux-graviton3
       fail-fast: false
     steps:
     - name: checkout
       uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # v3.1.0
 
+    - name: Mount NESSI CernVM-FS repository
+      uses: cvmfs-contrib/github-action-cvmfs@d4641d0d591c9a5c3be23835ced2fb648b44c04b # v3.1
+      with:
+          cvmfs_config_package: https://github.com/NorESSI/filesystem-layer/releases/download/latest/cvmfs-config-nessi_latest_all.deb
+          cvmfs_http_proxy: DIRECT
+          cvmfs_repositories: pilot.nessi.no
+
     - name: test eessi_archdetect.sh
       run: |
           export EESSI_MACHINE_TYPE=${{matrix.proc_cpuinfo}}
           export EESSI_MACHINE_TYPE=${EESSI_MACHINE_TYPE%%/*}
           export EESSI_PROC_CPUINFO=./tests/archdetect/${{matrix.proc_cpuinfo}}.cpuinfo
+          # check that printing of best match works correctly
           CPU_ARCH=$(./init/eessi_archdetect.sh cpupath)
           if [[ $CPU_ARCH == "$( cat ./tests/archdetect/${{matrix.proc_cpuinfo}}.output )" ]]; then
-              echo "Test for ${{matrix.proc_cpuinfo}} PASSED: $CPU_ARCH" >&2
+              echo "Test for ${{matrix.proc_cpuinfo}} PASSED: $CPU_ARCH"
           else
               echo "Test for ${{matrix.proc_cpuinfo}} FAILED: $CPU_ARCH" >&2
               exit 1
           fi
+          # check that $EESSI_SOFTWARE_SUBDIR_OVERRIDE is honored
+          export EESSI_SOFTWARE_SUBDIR_OVERRIDE='dummy/cpu'
+          CPU_ARCH=$(./init/eessi_archdetect.sh cpupath)
+          if [[ $CPU_ARCH == "${EESSI_SOFTWARE_SUBDIR_OVERRIDE}" ]]; then
+              echo "Test for picking up on \$EESSI_SOFTWARE_SUBDIR_OVERRIDE PASSED"
+          else
+              echo "Test for picking up on \$EESSI_SOFTWARE_SUBDIR_OVERRIDE FAILED" >&2
+              exit 1
+          fi
+          unset EESSI_SOFTWARE_SUBDIR_OVERRIDE
+          # check that printing of all matches works correctly (-a option for cpupath action)
+          CPU_ARCHES=$(./init/eessi_archdetect.sh -a cpupath)
+          if [[ $CPU_ARCHES == "$( cat ./tests/archdetect/${{matrix.proc_cpuinfo}}.all.output )" ]]; then
+              echo "Test for ${{matrix.proc_cpuinfo}} PASSED: $CPU_ARCHES"
+          else
+              echo "Test for ${{matrix.proc_cpuinfo}} FAILED: $CPU_ARCHES" >&2
+              exit 1
+          fi
+          # Check all those architectures actually exist (if this EESSI version has been populated already)
+          if [ -d ${EESSI_PREFIX}/software/linux ]; then
+            for dir in $(echo "$CPU_ARCHES" | tr ':' '\n'); do
+                # Search all EESSI versions as we may drop support at some point
+                ls -d ${EESSI_PREFIX}/software/linux/${dir}
+            done
+          fi
diff --git a/init/eessi_archdetect.sh b/init/eessi_archdetect.sh
index 81846658c7..236ac5a367 100755
--- a/init/eessi_archdetect.sh
+++ b/init/eessi_archdetect.sh
@@ -70,7 +70,7 @@ check_allinfirst(){
 cpupath(){
     # If EESSI_SOFTWARE_SUBDIR_OVERRIDE is set, use it
     log "DEBUG" "cpupath: Override variable set as '$EESSI_SOFTWARE_SUBDIR_OVERRIDE' "
-    [ $EESI_SOFTWARE_SUBDIR_OVERRIDE ] && echo ${EESSI_SOFTWARE_SUBDIR_OVERRIDE} && exit
+    [ $EESSI_SOFTWARE_SUBDIR_OVERRIDE ] && echo ${EESSI_SOFTWARE_SUBDIR_OVERRIDE} && exit
 
     # Identify the best matching CPU architecture from a list of supported specifications for the host CPU
     # Return the path to the installation files in NESSI of the best matching architecture