Re: [gentoo-user] Re: /dev/ttyUSB* group changed from uucp to root?

[Mike Gilbert]

On Thu, Sep 25, 2014 at 11:28 AM, Grant Edwards
<grant.b.edwards@×××××.com> wrote:
> On 2014-09-25, Mike Gilbert <floppym@g.o> wrote:
>> On Wed, Sep 24, 2014 at 6:28 PM, Grant Edwards
>><grant.b.edwards@×××××.com> wrote:
>>> On 2014-09-24, Neil Bothwick <neil@××××××××××.uk> wrote:
>>>> On Wed, 24 Sep 2014 19:42:56 +0000 (UTC), Grant Edwards wrote:
>>>>
>>>>> After an update yesterday, I've noticed that the group assigned to
>>>>> ttyUSB devices has changed from uucp to root.  Non-USB serial ports
>>>>> still seem to be uucp.
>>>>
>>>> What did you update? They are still root:uucp here.
>>>
>>> Several things got updated, but the most likely suspect is probably
>>> sys-fs/udev-215-r1 => sys-fs/udev-216.  But, I don't see any changes
>>> in the default rules to account for the change in behavior.
>>>
>>
>> I'm running systemd-216, and I see this in
>> /lib/udev/rules.d/50-udev-default.rules:
>>
>> KERNEL=="tty[A-Z]*[0-9]|pppox[0-9]*|ircomm[0-9]*|noz[0-9]*|rfcomm[0-9]*",
>> GROUP="uucp"
>>
>> I suppose it is possible that some later rule overrides it, but I
>> don't see anything obvious.
>
> Yes, I saw that rule (and it hasn't changed recently).  I also have a
> rule that creates a symlink for a certain USB-serial adapter in
> /etc/udev/rules.d/99-user.rules:
>
> SUBSYSTEMS=="usb",\
>  ATTRS{product}=="FT232R USB UART",\
>  ATTRS{serial}=="AH026Q3X",\
>  KERNEL=="ttyUSB*",\
>  SYMLINK+="ttyDBG",\
>  GROUP="uucp"
>
> I didn't used to need to set the GROUP in that rule, the device file
> just defaulted to having a group of uucp. Yesterday, I had to add the
> "GROUP" command to get the behavior I always used to get without it.

You could try using udevadm test to see what rules are firing.

sudo udevadm test --action=add /sys/class/tty/ttyUSB0