Make sure to actual check for EESSI_ACCELERATOR_TARGET_OVERRIDE to be defined

Author: Caspar van Leeuwen

EESSI-install-software.sh

@@ -156,17 +156,22 @@ else
       # set EESSI_ACCELERATOR_TARGET and the if-condition later in this script which checks if EESSI_ACCELERATOR_TARGET
       # is equal to EESSI_ACCELERATOR_TARGET_OVERRIDE will fail 
       # See https://github.com/EESSI/software-layer-scripts/pull/59#issuecomment-3173593882
-      if [ -z $EESSI_ACCEL_SOFTWARE_SUBDIR_OVERRIDE ]; then
-          mkdir -p ${EESSI_PREFIX}/software/${EESSI_OS_TYPE}/${EESSI_SOFTWARE_SUBDIR_OVERRIDE}/${EESSI_ACCELERATOR_TARGET_OVERRIDE}/modules/all
-      else
-          # At runtime, one might want to use a different CPU subdir for a given accelerator. E.g. one could use
-          # a zen2 CPU subdir on a zen4 node if the required GPU software isn't available in the zen4 tree.
-          # At build time, this doesn't make a lot of sense: we'd probably build in a CPU prefix that is different
-          # from what the code will be optimized for, and we wouldn't want that
-          msg="When building the software subdirectory for the CPU should almost certainly be that of the host."
-          msg="$msg If you think this is incorrect, please implement behaviour that makes sense in "
-          msg="$msg EESSI-software-installation.sh, essentially replacing this error."
-          fatal_error "$msg"
+      if [ -n $EESSI_ACCELERATOR_TARGET_OVERRIDE ]; then
+          # Note that ${EESSI_PREFIX}/software/${EESSI_OS_TYPE}/${EESSI_SOFTWARE_SUBDIR_OVERRIDE}/${EESSI_ACCELERATOR_TARGET_OVERRIDE}/modules/all
+          # is only the correct path if EESSI_ACCEL_SOFTWARE_SUBDIR_OVERRIDE is not set
+          if [ -z $EESSI_ACCEL_SOFTWARE_SUBDIR_OVERRIDE ]; then
+              mkdir -p ${EESSI_PREFIX}/software/${EESSI_OS_TYPE}/${EESSI_SOFTWARE_SUBDIR_OVERRIDE}/${EESSI_ACCELERATOR_TARGET_OVERRIDE}/modules/all
+          else
+              # At runtime, one might want to use a different CPU subdir for a given accelerator. E.g. one could use
+              # a zen2 CPU subdir on a zen4 node if the required GPU software isn't available in the zen4 tree.
+              # At build time, this doesn't make a lot of sense: we'd probably build in a CPU prefix that is different
+              # from what the code will be optimized for, and we wouldn't want that
+              # So this message _should_ never be printed...
+              msg="When building the software subdirectory for the CPU should almost certainly be that of the host."
+              msg="$msg If you think this is incorrect, please implement behaviour that makes sense in "
+              msg="$msg EESSI-software-installation.sh, essentially replacing this error."
+              fatal_error "$msg"
+          fi
       fi
   )
 fi