Reading from the usermod manual, this is expected behavior: -G, --groups GROUP1[,GROUP2,...[,GROUPN]]] A list of supplementary groups which the user is also a member of. Each group is separated from the next by a comma, with no intervening whitespace. The groups are subject to the same restrictions as the group given with the -g option.
If the user is currently a member of a group which is not listed, the user will be removed from the group. This behaviour can be changed via the -a option, which appends the user to the current supplementary group list. ** Project changed: ubuntu-mate => ubuntu ** Package changed: ubuntu => shadow (Ubuntu) ** Changed in: shadow (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to shadow in Ubuntu. https://bugs.launchpad.net/bugs/1682759 Title: usermod -G username:www-data remove primary user from sudoers group Status in shadow package in Ubuntu: Invalid Bug description: When adding a user with usermod -G usermod:www-data removes the primary user from the sudoers group. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/shadow/+bug/1682759/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp