Workaround docker build error

Dockerfile.aarch64

@@ -16,6 +16,11 @@ RUN rm rootfs/var/lib/pacman/sync/*
 
 FROM scratch
 COPY --from=0 /archlinux/rootfs/ /
+
+# Workaround for 'failed to get layer'
+# https://stackoverflow.com/a/62409523/1124621
+RUN true
+
 COPY rootfs/alarm/ /
 
 ENV LANG=en_US.UTF-8

Dockerfile.x86_64

@@ -16,6 +16,11 @@ RUN rm rootfs/var/lib/pacman/sync/*
 
 FROM scratch
 COPY --from=0 /archlinux/rootfs/ /
+
+# Workaround for 'failed to get layer'
+# https://stackoverflow.com/a/62409523/1124621
+RUN true
+
 COPY rootfs/archlinux/ /
 
 ENV LANG=en_US.UTF-8