[nmglug] No GUI desktop=added info

[s at mnoble.net]

On Fri, Mar 16, 2018 okeefe at cybermesa.com wrote:
> > Here's the log file error:
> > #(EE) open /dev/fb0: permission denied#
> > after finding correct syntax for the log file ;)
Not sure how far from the real issue we are here, as X's use of the
framebuffer is I believe optional,  but the perms issues should be
easily fixable. A DM would run as some user with the correct
permissions, but since you're running startx as yourself any permission
issues are applying to your user.
My framebuffer 0 device is owned by group video:
sam at computer$ ls -l /dev/fb0 
crw-rw---- 1 root video 29, 0 Mar 16 12:00 /dev/fb0

If yours is similar maybe you need to be added to that group:
ubuntu at ubuntu$sudo usermod -a -G video ubuntu

> > Interestingly this last reboot booted straight into the guest
> > and lightdm (where that wm (sic) came from is beyond me!). Can't
> > login to any wm as me though. 
Hmm, there's so many possibilities of how the DMs are being shipped. I
hope you're getting good advice from Ubuntites on their forum. Seems
like whatever they're doing to enable easy guest access is getting in
our way here.

> >> $sudo /etc/init.d/somedm stop
is useful here.
You could try:
$sudo /etc/init.d/lightdm stop	#Or restart would be interesting.

Also note that Display Managers (gdm, kdm, lightdm, slim, xdm) are not
window managers, they're pretty much just there to launch X and give you
a login window. And they are not always (or even typically) tied to the
window manager/desktop environment that they 'come with'

I guess we skipped the part where you tell us if your using startx
intentially, or if it's something you started doing becouse your DM is
broken?

> Sorry for dribbling this in but I ran #who# and for the first time found
> that ubuntuguest has a DISPLAY value of (:0) EHO NO VALUE FOR ME,
> "Ubuntu". I had just run #export DISPLAY="0.0# logged in as me in the
> command line. However if I ctr+alt+f7 I am back in the ubuntuguest GUI. On

Yeah that sounds normal. It is probably possible for you to run your GUI
apps in guest's X session but that won't be a solution excepting some
scenario where (against Ted's correct advice) you've given up on fixing
the underlying issue and are trying to e.g. run Thunderbird that one
last time to do an export.
It'd go something like:
Open terminal emulator in guest session
ubuntuguest at ubuntu$xhost + 	#Lots of more granular ways to do this with xauth/Xauthority but xhost + should just disable all that.
ubuntuguest at ubuntu$su ubuntu	#su - ubuntu would spawn a login shell, but this way you'll keep the DISPLAY=:0 from ubuntuguest's env.
ubuntu at ubuntu$xclock		#xclock or xlogo from x11-apps are my goto for a test like this. Most real stuff will want other environment stuff from the session, dbus and the like.

-- 
sam