diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index e3923ae..2ffd340 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -32,16 +32,20 @@ jobs:
       run: |
         sudo apt-get install -y gettext gawk
         pip install -r requirements.txt
-    - name: Package Folder Prefix For circuitpython-build-tools (Community Bundle Specific)
-      id: pkg-folder
+    - name: Build assets
+      env:
+        FILENAME_PREFIX: ${{ steps.repo-name.outputs.repo-name }}
       run: |
-        echo prefix=$(
+        prefix=$(
         ls -RUx |
         gawk -F '\n' '{ match($1, /(drivers|helpers)\/(.+)\/(.+)\:/, arr) ; if (length(arr[0]) > 0 && match(arr[3], arr[2]) > 0) printf "%s, ", arr[3] }' |
-        gawk '{ trimmed = substr($0, 1, length($0) - 2) ; print "\"" trimmed "\"" }'
-        ) >> $GITHUB_OUTPUT
-    - name: Build assets
-      run: circuitpython-build-bundles --filename_prefix ${{ steps.repo-name.outputs.repo-name }} --library_location libraries --library_depth 2 --package_folder_prefix ${{ steps.pkg-folder.outputs.prefix }}
+        gawk '{ print substr($0, 1, length($0) - 2) }'
+        )
+        if [ -z "$prefix" ]; then
+          echo "::error::no package folders matched under libraries/"
+          exit 1
+        fi
+        circuitpython-build-bundles --filename_prefix "$FILENAME_PREFIX" --library_location libraries --library_depth 2 --package_folder_prefix "$prefix"
     - name: Upload Release Assets
       uses: shogo82148/actions-upload-release-asset@v1
       with:
diff --git a/build.sh b/build.sh
index 94ed85f..03c1ca1 100755
--- a/build.sh
+++ b/build.sh
@@ -29,7 +29,12 @@ set -e
 P=$(
 ls -RUx |
 gawk -F '\n' '{ match($1, /(drivers|helpers)\/(.+)\/(.+)\:/, arr) ; if (length(arr[0]) > 0 && match(arr[3], arr[2]) > 0) printf "%s, ", arr[3] }' |
-gawk '{ trimmed = substr($0, 1, length($0) - 2) ; print "\"" trimmed "\"" }'
+gawk '{ print substr($0, 1, length($0) - 2) }'
 )
 
+if [ -z "$P" ]; then
+    echo "error: no package folders matched under libraries/" >&2
+    exit 1
+fi
+
 circuitpython-build-bundles --filename_prefix circuitpython-community-bundle --library_location libraries --library_depth 2 --package_folder_prefix "$P"