With `rprivate` there exists a race where a reference to a mount has propagated to the new namespace, when `rprivate` is set the parent namespace is not able to remove the mount due to that reference. With `rslave` unmounts will propagate correctly into the namespace and prevent the sort of transient errors that are possible with `rprivate`. This is a similar fix to https://github.com/opencontainers/runc/pull/1500/commits/117c92745bd098bf05a69489b7b78cac6364e1d0 Signed-off-by: Brian Goff <cpuguy83@gmail.com> (cherry picked from commit 5ede64d63fec0b9d4cf921b6f8fb946e65287538) Signed-off-by: Sebastiaan van Stijn <github@gone.nl>