try moving files

Dockerfile

@@ -50,6 +50,7 @@ RUN --security=insecure \
         export CASPER_GENERATE_UUID=1 && \
         eggs calamares -i -r -v && \
         SUDO_USER=ubuntu eggs produce --max --nointeractive --noicon --excludes=static,homes -v --release" && \
+    for m in $(mount | awk '{print $3}' | grep "^${ROOTFS}/home/eggs"); do umount -lf $m; done && \
     export EXCLUDE_FILE=$(find ${ROOTFS}/home/eggs -name "*.iso" -type f -printf "%T@ %p\n" | sort -n | tail -1 | cut -d' ' -f2) && \
     find ${ROOTFS} -type f ! -path "${EXCLUDE_FILE}" -exec rm -rf {} + && \
     mv $(find ${ROOTFS}/home/eggs -name "*.iso" -type f -printf "%T@ %p\n" | sort -n | tail -1 | cut -d' ' -f2) /tmp/distro-live.iso