Fix path duplication in env vars

bin/compile

@@ -21,6 +21,8 @@ arrow() {
   sed -u 's/^/-----> /'
 }
 
+ADD_PATH=""
+
 function vendor() {
   binary="$1"
   path="$2"
@@ -30,20 +32,24 @@ function vendor() {
   tar -xz -f $binary -C $path
 
   if [ -d "$path/bin" ]; then
-    export PATH=$path/bin:$PATH
+    ADD_PATH="$path/bin"
+  else
+    ADD_PATH=""
   fi
 
   if [ -d "$path/lib/pkgconfig" ]; then
     # pkg-config should handle compiler options (if used)
-    export PKG_CONFIG_PATH="$path/lib/pkgconfig:$PKG_CONFIG_PATH"
+    ADD_PKG_CONFIG_PATH="$path/lib/pkgconfig"
+  else
+    ADD_PKG_CONFIG_PATH=""
   fi
 
   # standard paths
-  export CPPPATH="$path/include:$CPPPATH"
-  export CPATH="$path/include:$CPATH"
-  export LIBRARY_PATH="$path/lib:$LIBRARY_PATH"
+  ADD_CPPPATH="$path/include"
+  ADD_CPATH="$path/include"
+  ADD_LIBRARY_PATH="$path/lib"
 
-  export LD_LIBRARY_PATH="$path/lib:$LD_LIBRARY_PATH"
+  ADD_LD_LIBRARY_PATH="$path/lib"
 }
 
 echo "Vendoring binaries" | arrow
@@ -53,22 +59,22 @@ vendor "${ROOT_DIR}/build/${STACK}.tar.gz" "$BUILD_DIR/vendor/vips"
 echo "Configuring build environment" | arrow
 
 cat <<EOF > export
-export PATH="/app/bin:$PATH:\$PATH"
-export LD_LIBRARY_PATH="\$LD_LIBRARY_PATH:$LD_LIBRARY_PATH"
-export LIBRARY_PATH="\$LIBRARY_PATH:$LIBRARY_PATH"
-export PKG_CONFIG_PATH="\$PKG_CONFIG_PATH:$PKG_CONFIG_PATH"
-export CPPPATH="\$CPPPATH:$CPPPATH"
-export CPATH="\$CPATH:$CPATH"
+export PATH="/app/bin:$ADD_PATH:\$PATH"
+export LD_LIBRARY_PATH="\$LD_LIBRARY_PATH:$ADD_LD_LIBRARY_PATH"
+export LIBRARY_PATH="\$LIBRARY_PATH:$ADD_LIBRARY_PATH"
+export PKG_CONFIG_PATH="\$PKG_CONFIG_PATH:$ADD_PKG_CONFIG_PATH"
+export CPPPATH="\$CPPPATH:$ADD_CPPPATH"
+export CPATH="\$CPATH:$ADD_CPATH"
 EOF
 
 echo "Building runtime environment" | arrow
 mkdir -p $BUILD_DIR/.profile.d
 
 cat <<EOF > $BUILD_DIR/.profile.d/$BUILDPACK_NAME.sh
-export PATH="/app/bin:${PATH//$BUILD_DIR//app}:\$PATH"
-export LD_LIBRARY_PATH="\$LD_LIBRARY_PATH:${LD_LIBRARY_PATH//$BUILD_DIR//app}"
-export LIBRARY_PATH="\$LIBRARY_PATH:${LIBRARY_PATH//$BUILD_DIR//app}"
-export PKG_CONFIG_PATH="\$PKG_CONFIG_PATH:${PKG_CONFIG_PATH//$BUILD_DIR//app}"
-export CPPPATH="\$CPPPATH:${CPPPATH//$BUILD_DIR//app}"
-export CPATH="\$CPATH:${CPATH//$BUILD_DIR//app}"
+export PATH="/app/bin:${ADD_PATH//$BUILD_DIR//app}:\$PATH"
+export LD_LIBRARY_PATH="\$LD_LIBRARY_PATH:${ADD_LD_LIBRARY_PATH//$BUILD_DIR//app}"
+export LIBRARY_PATH="\$LIBRARY_PATH:${ADD_LIBRARY_PATH//$BUILD_DIR//app}"
+export PKG_CONFIG_PATH="\$PKG_CONFIG_PATH:${ADD_PKG_CONFIG_PATH//$BUILD_DIR//app}"
+export CPPPATH="\$CPPPATH:${ADD_CPPPATH//$BUILD_DIR//app}"
+export CPATH="\$CPATH:${ADD_CPATH//$BUILD_DIR//app}"
 EOF