demo: use runc for buildah

Signed-off-by: Mikko Ylinen <[email protected]>

Author: mythi

demo/build-image.sh

@@ -20,7 +20,7 @@ TAG=${TAG:-devel}
 if [ -z "$BUILDER" -o "$BUILDER" = 'docker' -o "$BUILDER" = 'podman' ] ; then
     ${BUILDER} build --pull -t ${IMG}:${TAG} "$CWD/$DIR/"
 elif [ "$BUILDER" = 'buildah' ] ; then
-    buildah bud  --pull-always --log-level trace -t ${IMG}:${TAG} "$CWD/$DIR/"
+    BUILDAH_RUNTIME=runc buildah bud  --pull-always --log-level trace -t ${IMG}:${TAG} "$CWD/$DIR/"
 else
     (>&2 echo "Unknown builder $BUILDER")
     exit 1