non-Unity flavours and Mir

[Scott Kitterman]

On Friday, June 14, 2013 11:41:29 AM Marc Deslauriers wrote:
> On 13-06-14 11:33 AM, Scott Kitterman wrote:
> > On Friday, June 14, 2013 11:15:17 AM Marc Deslauriers wrote:
> >> On 13-06-14 11:04 AM, Scott Kitterman wrote:
> >>> On Friday, June 14, 2013 03:54:32 PM Jonathan Riddell wrote:
> >>>> Here's a discussion I half started as part of vUDS.
> >>>> 
> >>>> The switch to Mir in Ubuntu seems pretty risky for the existance of
> >>>> Kubuntu, I wonder if other flavours have the same probable problem.
> >>>> 
> >>>> KWin dev has opinions on the subject
> >>>> http://blog.martin-graesslin.com/blog/2013/05/mir-in-kubuntu/ From the
> >>>> 
> >>>> architecture section on that blog post:
> >>>>  "Mir’s architecture is centered around Unity. It is difficult to
> >>>>  really
> >>>>  understand the architecture of Mir as the specification is so full of
> >>>>  buzz-words that I don’t understand it [5]. From all I can see and
> >>>>  understand Unity Next is a combination of window manager and desktop
> >>>>  shell implemented on top of Mir. How exactly this is going to look
> >>>>  like I do not know. Anyway it does not fit our design of having
> >>>>  desktop shell and window manager separated and we do not know whether
> >>>>  Mir would support that. We also do not know whether Mir would allow
> >>>>  any other desktop shell except Unity Next, given that this is the main
> >>>>  target. Wayland on the other hand is designed to have more than one
> >>>>  compositor implementations. Using KWin as a session compositor is an
> >>>>  example in the spec."
> >>>> 
> >>>> and on protocol
> >>>> 
> >>>>  "But it gets worse, the protocol between Mir server and Mir clients
> >>>>  is defined as not being stable. In fact it’s promised that it will
> >>>>  break. That’s a huge problem, I would even call it a showstopper....
> >>>>  Given that the protocol may change any time and given that the whole
> >>>>  thing is developed for the needs of Unity we have to expect that the
> >>>>  server libraries are not binary compatible or that old version of the
> >>>>  server libraries cannot talk with the latest client libraries"
> >>>> 
> >>>> Canonical was going to port LightDM to Wayland but now does not plan
> >>>> to so someone else would have to do this.  KDE might be interested
> >>>> but more likely will switch to SDDM.
> >>>> 
> >>>> For Kubuntu the options are:
> >>>> - Use Mir - infeasable as upstream can't support it as described above
> >>>> - Use Wayland with packages from Debian and hope we can make those
> >>>> packages
> >>>> 
> >>>>   live with Mir as best as possible
> >>>> 
> >>>> - End of Kubuntu
> >>>> 
> >>>> The second options is the one I'm expecting.  It's completely unknown
> >>>> how much it means Kubuntu and other flavours will need to maintain X
> >>>> and Wayland packages, hopefully not much (it's hardly our speciality)
> >>>> and hopefully Debian and Ubuntu Desktop will support it enough.
> >>>> 
> >>>> I don't think there's a public timeline for Mir so we don't know when
> >>>> this will hit us, presumably in the next year.
> >>>> 
> >>>> Other flavours I think are this:
> >>>> Mythbuntu: not evaluated, hope to do so once NVideo and AMD provide
> >>>> drivers
> >>>> Lubuntu: not evaluated, hope to use X and GTK
> >>>> ubuntustudio: I've heard both that they use xfce based on xubuntu and
> >>>> will follow them, and "aiming for users to choose whatever desktop
> >>>> environment they want"
> >>>> 
> >>>> Any other flavours got an opinions?
> >>>> 
> >>>> Are there any misconceptions I have in the above?
> >>> 
> >>> Given that mesa is going to be heavily patched to support Mir, I
> >>> question
> >>> the long term feasibility of supporting Wayland in Ubuntu.
> >> 
> >> How would adding a new backend to mesa result in it being "heavily
> >> patched"? Why would adding a new backend to mesa affect the other
> >> backends, including Wayland?
> > 
> > Upstream kwin tells us they already see bug reports from Kubuntu users due
> > to mesa changes to support Unity.  I don't think it's just a new back
> > end.
> Oh? That's quite odd, I don't see any Unity patches in the mesa package
> in saucy. There are a couple of build fixes, and other trivial things,
> but nothing that should be problematic.
> 
> Do you have any more details, or opened bugs about the issues?

I don't.  I don't know a lot about the display stack details.  I'm basing this 
on feedback from kwin upstream.

Scott K