unable to remove directory /run/lock when uninstalling kea in deb-based systems

On all debians and ubuntus, removing isc-kea-common (apt-get remove -y isc-kea-common) ends up with a warning, although it doesn't prevent the uninstall:

 dpkg: warning: while removing isc-kea-common, unable to remove directory '/run/lock': Device or resource busy - directory may be a mount point?`

https://jenkins.aws.isc.org/job/kea-manual/job/check-pkgs/42/execution/node/294/log/