Comment 3 for bug 1729357

Well, there is the slight problem that every single Ubuntu server install comes with newgidmap installed today so I think we do need to be careful with releasing a fix for this as there may well be users of LXC/LXD that also rely on negative groups for access control on their system.

Your suggestion to chmod 000 newgidmap would break those users and is certainly not something that'd be suitable for a security upload.