Description of problem:
When I try to burn an iso to a disk with k3b (started from command line) as a regular user that is in the cdrom group, I get an error that cdrecord has no permission to open the device.

Version-Release number of selected component (if applicable):
k3b-1:17.12.3-1.fc28.x86_64

How reproducible:
Very

Steps to Reproduce:
1. Open k3b either from command line or GUI.
2. Go to More actions... -> Burn Image...
3. Select an ISO and writing configuration doesn't matter.
4. Press start.

Actual results:
It starts attempting to write until I get an error that cdrecord has no permission to open the device. The debug log is here: https://web.archive.org/web/20180615213839/https://pastebin.com/p8Qy0xJm 

Expected results:
K3b to write to disk as normal, maybe even Polkit prompting for a password.

Additional info:
When I tried this on Tuesday, I wasn't in the cdrom group and when I tried in root I got a message in the Settings -> Devices: "In order to give K3b full access to the writer device the current user needs be added to a group cdrom.
The Permission helper that could do this for you was not enabled during build.
Please rebuild the package with the Permission helper enabled or contact your distribution". Root isn't in the cdrom group. I have no problem except warnings about my status of root when I startup k3b and write an iso.

Suggestion:
It would be nice if the message that showed up when a user not in the cdrom group started k3b at least had instructions on how to add themselves to it properly for this application.