I have debian8, (Jessie) and I am trying to add a user to the dialout group. 
Alas, that group doesn't exist. I would prefer not to add the user to the root or sudo group. 

what should I do?

```
~$ groups
user1 user2 cdrom floppy sudo audio dip video plugdev netdev lpadmin scanner bluetooth

```

How can I create the dialout group?

```
$sudo usermod -a -G dialout user1

```

executes without error, but I cannot see that I am a member of the dialout group, nor that any dialout group exists