Fixes to dpctl-post-link prior changes gh-1081

conda-recipe/build.sh

@@ -33,5 +33,7 @@ fi
 
 # need to create this folder so ensure that .dpctl-post-link.sh can work correctly
 mkdir -p $PREFIX/etc/OpenCL/vendors
+echo "dpctl creates symbolic link to system installed /etc/OpenCL/vendors/intel.icd as a work-around." > $PREFIX/etc/OpenCL/vendors/.dpctl_readme
 
 cp $RECIPE_DIR/dpctl-post-link.sh $PREFIX/bin/.dpctl-post-link.sh
+cp $RECIPE_DIR/dpctl-pre-unlink.sh $PREFIX/bin/.dpctl-pre-unlink.sh

conda-recipe/dpctl-post-link.sh

@@ -1,8 +1,9 @@
 #!/usr/bin/bash
 
 systemwide_icd=/etc/OpenCL/vendors/intel.icd
-local_vendors=$CONDA_PREFIX/etc/OpenCL/vendors/
+local_vendors=$PREFIX/etc/OpenCL/vendors/
+icd_fn=$local_vendors/intel-ocl-gpu.icd
 
-if [[ -f $systemwide_icd && -d $local_vendors && ! -f $local_vendors/intl-ocl-gpu.icd ]]; then
-    ln -s $systemwide_icd  $local_vendors/intel-ocl-gpu.icd
+if [[ -f $systemwide_icd && -d $local_vendors && ! -f $icd_fn ]]; then
+    ln -s $systemwide_icd $icd_fn
 fi

conda-recipe/dpctl-pre-unlink.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/bash
+
+local_vendors=$PREFIX/etc/OpenCL/vendors/
+icd_fn=$local_vendors/intel-ocl-gpu.icd
+
+if [[ -L $icd_fn ]]; then
+    rm $icd_fn
+fi