diff --git a/build_library/sysext_prod_builder b/build_library/sysext_prod_builder
index a1db9acd7d..73afbb6cb4 100755
--- a/build_library/sysext_prod_builder
+++ b/build_library/sysext_prod_builder
@@ -33,8 +33,7 @@ create_prod_sysext() {
   local grp_pkg="$7"
   local pkginfo="${8:-}"
 
-  local pkginfo_opt=""
-  local manglefs_opt=""
+  local -a build_sysext_opts=()
 
   local msg="Installing ${grp_pkg}' in sysext ${name}.raw"
 
@@ -44,12 +43,12 @@ create_prod_sysext() {
       die "Sysext build '${grp_pkg}': unable to find package info at '${output_dir}/${pkginfo}'."
     fi
     msg="${msg} w/ package info '${pkginfo}'"
-    pkginfo_opt="--base_pkginfo=${output_dir}/${pkginfo}"
+    build_sysext_opts+=( "--base_pkginfo=${output_dir}/${pkginfo}" )
   fi
 
   # Include FS mangle script if present
   if [[ -x "${BUILD_LIBRARY_DIR}/sysext_mangle_${name}" ]] ; then
-    manglefs_opt="--manglefs_script=${BUILD_LIBRARY_DIR}/sysext_mangle_${name}"
+    build_sysext_opts+=( "--manglefs_script=${BUILD_LIBRARY_DIR}/sysext_mangle_${name}" )
     msg="${msg}, FS mangle script 'sysext_mangle_${name}'"
   fi
 
@@ -60,7 +59,7 @@ create_prod_sysext() {
             --image_builddir="${workdir}/sysext-build" \
             --squashfs_base="${base_sysext}" \
             --generate_pkginfo \
-            ${manglefs_opt} ${pkginfo_opt} \
+            "${build_sysext_opts[@]}" \
             "${name}" "${grp_pkg}"
 
   sudo mv "${workdir}/sysext-build/${name}.raw" "${workdir}/sysext-build/${name}_pkginfo.raw" \
diff --git a/run_local_tests.sh b/run_local_tests.sh
index f13c2e6bff..046df79d5f 100755
--- a/run_local_tests.sh
+++ b/run_local_tests.sh
@@ -51,10 +51,10 @@ function set_vars() {
   # Read by the mantle container.
   # The local directory ("pwd") will be mounted to /work/ in the container.
   cat > sdk_container/.env <<EOF
-export export QEMU_IMAGE_NAME="/work/__build__/images/images/${arch}-usr/latest/flatcar_production_image.bin"
-export QEMU_UEFI_BIOS="/work/__build__/images/images/${arch}-usr/latest/flatcar_production_qemu_uefi_efi_code.fd"
-export QEMU_UPDATE_PAYLOAD="/work/__build__/images/images/${arch}-usr/latest/flatcar_test_update.gz"
-export PARALLEL_TESTS=${parallel}                                                     
+export QEMU_IMAGE_NAME="/work/__build__/images/images/${arch@Q}-usr/latest/flatcar_production_image.bin"
+export QEMU_UEFI_BIOS="/work/__build__/images/images/${arch@Q}-usr/latest/flatcar_production_qemu_uefi_efi_code.fd"
+export QEMU_UPDATE_PAYLOAD="/work/__build__/images/images/${arch@Q}-usr/latest/flatcar_test_update.gz"
+export PARALLEL_TESTS=${parallel@Q}
 EOF
 
   export MAX_RETRIES=5
@@ -62,7 +62,7 @@ EOF
 }
 #--
 
-function run_local_tests() {
+function run_local_tests() (
   local arch="${1:-amd64}"
   if [[ $# -gt 0 ]] ; then shift; fi
   local parallel="${1:-2}"
@@ -98,7 +98,7 @@ function run_local_tests() {
     test_run "${arch}" qemu_update
   fi
 
-}
+)
 # --
 
 
diff --git a/run_sdk_container b/run_sdk_container
index 4bdbf60783..43f6b78058 100755
--- a/run_sdk_container
+++ b/run_sdk_container
@@ -51,7 +51,7 @@ usage() {
 }
 # --
 
-update_versionfile="true"
+update_versionfile=x
 while [ 0 -lt $# ] ; do
     case "$1" in
     -h) usage; exit 0;;
@@ -66,7 +66,7 @@ while [ 0 -lt $# ] ; do
     -C) custom_image="$2";  shift; shift;;
     -U) sdk_version="$(get_sdk_version_from_versionfile)"
         os_version="$(get_version_from_versionfile)"
-        update_versionfile="false"
+        update_versionfile=
         shift;;
     *) break;;
     esac
@@ -79,7 +79,7 @@ else
     container_image_name="$sdk_container_common_registry/flatcar-sdk-${arch}:${docker_sdk_vernum}"
 fi
 
-if [[ "${update_versionfile}" == true ]] ; then
+if [[ -n ${update_versionfile} ]] ; then
     create_versionfile "$sdk_version" "$os_version"
 fi