diff --git a/build.sh b/build.sh
index df5fda3..ad9ced6 100644
--- a/build.sh
+++ b/build.sh
@@ -3,47 +3,59 @@
 # Tell build process to exit if there are any errors.
 set -oue pipefail
 
+# Helper functions.
+get_yaml_array() {
+    mapfile -t "$1" < <(yq "$2" < /usr/etc/ublue-recipe.yml)
+}
+
 # Add custom repos.
-repos=$(yq '.extrarepos[]' < /usr/etc/ublue-recipe.yml)
-if [[ -n "$repos" ]]; then
+get_yaml_array repos '.extrarepos[]'
+if [[ ${#repos[@]} -gt 0 ]]; then
     echo "-- Adding repos defined in recipe.yml --"
-    for repo in $(echo -e "$repos"); do \
-        wget $repo -P /etc/yum.repos.d/; \
+    for repo in "${repos[@]}"; do
+        wget "$repo" -P /etc/yum.repos.d/
     done
     echo "---"
 fi
 
 # Run scripts.
-echo "-- Running scripts defined in recipe.yml --"
-buildscripts=$(yq '.scripts[]' < /usr/etc/ublue-recipe.yml)
-for script in $(echo -e "$buildscripts"); do \
-    echo "Running: ${script}" && \
-    /tmp/scripts/$script; \
-done
-echo "---"
+get_yaml_array buildscripts '.scripts[]'
+if [[ ${#buildscripts[@]} -gt 0 ]]; then
+    echo "-- Running scripts defined in recipe.yml --"
+    for script in "${buildscripts[@]}"; do
+        echo "Running: ${script}"
+        /tmp/scripts/"$script"
+    done
+    echo "---"
+fi
 
 # Remove the default firefox (from fedora) in favor of the flatpak.
 rpm-ostree override remove firefox firefox-langpacks
 
 # Install RPMs.
-echo "-- Installing RPMs defined in recipe.yml --"
-rpm_packages=$(yq '.rpms[]' < /usr/etc/ublue-recipe.yml)
-for pkg in $(echo -e "$rpm_packages"); do \
-    echo "Installing: ${pkg}" && \
-    rpm-ostree install $pkg; \
-done
-echo "---"
+get_yaml_array install_rpms '.rpms[]'
+if [[ ${#install_rpms[@]} -gt 0 ]]; then
+    echo "-- Installing RPMs defined in recipe.yml --"
+    for pkg in "${install_rpms[@]}"; do
+        echo "Installing: ${pkg}"
+        rpm-ostree install $pkg
+    done
+    echo "---"
+fi
 
 # Install yafti to install flatpaks on first boot, https://github.com/ublue-os/yafti.
 pip install --prefix=/usr yafti
 
-# Add a package group for yafti using the packages defined in recipe.yml.
-flatpaks=$(yq '.flatpaks[]' < /tmp/ublue-recipe.yml)
-# Only try to add package groups if some flatpaks are defined in the recipe.
-if [[ -n "$flatpaks" ]]; then            
+# Add a new yafti "package group" called Custom, for the packages defined in recipe.yml.
+# Only adds the package group if some flatpaks are defined in the recipe.
+get_yaml_array flatpaks '.flatpaks[]'
+if [[ ${#flatpaks[@]} -gt 0 ]]; then
+    echo "-- yafti: Adding Flatpaks defined in recipe.yml --"
     yq -i '.screens.applications.values.groups.Custom.description = "Flatpaks defined by the image maintainer"' /usr/etc/yafti.yml
     yq -i '.screens.applications.values.groups.Custom.default = true' /usr/etc/yafti.yml
-    for pkg in $(echo -e "$flatpaks"); do \
+    for pkg in "${flatpaks[@]}"; do
+        echo "Adding to yafti: ${pkg}"
         yq -i ".screens.applications.values.groups.Custom.packages += [{\"$pkg\": \"$pkg\"}]" /usr/etc/yafti.yml
     done
-fi
\ No newline at end of file
+    echo "---"
+fi