Xdummy cannot be used in Xenial
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
xserver-xorg-video-dummy (Ubuntu) |
Confirmed
|
High
|
Unassigned |
Bug Description
Xdummy is used by several systems for remote display, such as xpra (http://
Unfortunately, since Xenial, it is completely impossible to use Xdummy for anything like that, because of the way in which permissions are set up for running X servers. This results in a serious compromise on the possibility of running remote displays systems on ubuntu. In fact, the latter can only rely on Xvfb with a less than optimal experience.
Most important,
Trying to run Xdummy from a console session results in
/usr/lib/
It should be possible to start Xdummy from an ssh session. Xdummy is a 'dummy' display driver. It does not touch real hardware. There is no need to prevent users who are not on the console from starting it. In fact, it is not clear what is the purpose of taking the effort of packaging and shipping Xdummy at all, if it cannot be used for the tasks it is intended for.
See also:
http://
The Xpra developer, whose availability to help is always excellent, explicitly states that:
- it is not possible to use xdummy with almost all Ubuntu releases [in fact the problem is Xenial. Before xenial, xdummy required some tweaks, but worked]
- xpra needs to be compiled with the --without-Xdummy on Ubuntu because of this
- There is nothing that can be done in xpra, because this is an OS permission problem
ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xserver-
ProcVersionSign
Uname: Linux 4.4.0-22-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: KDE
Date: Mon Jun 6 11:54:50 2016
EcryptfsInUse: Yes
InstallationDate: Installed on 2013-12-12 (906 days ago)
InstallationMedia: Kubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
SourcePackage: xserver-
UpgradeStatus: Upgraded to xenial on 2016-04-21 (45 days ago)
Changed in xserver-xorg-video-dummy (Ubuntu): | |
importance: | Undecided → High |
After some investigation, the problem seems to be in the Xorg.wrap wrapper that is way too picky.
1) Without the wrapper Xdummy cannot be executed because it tries to open some virtual console and fails
2) With the wrapper Xdummy cannot be executed either because
a) you need to modify the Xwrapper.conf file to let anybody run it first
b) The wrapper protests that it cannot run with elevated privileges and options for Xorg including -logfile and -configdir, but these are obviously required if one wants to start Xdummy under the control of another application such as Xpra
To me, it is totally unclear why:
a) Xdummy should need to run with privilege at all otherwise Xorg messes with the virtual consoles.
b) The wrapper cannot have its own options making it more flexible and a group to manage it, so that only the users with appropriate permissions (in the appropriate group) can start the wrapper with the options relaxing its behavior (e.g. allowing -logfile and -confdir)