Caffeine can't connect to display since Ubuntu 15.04 upgrade

[halfbeing]

Today I upgraded from Ubuntu 14.10 to 15.04. Since then I have been unable to launch Caffeine because it can't connect to the display. I get the following error message:

Traceback (most recent call last):
  File "/usr/bin/caffeine", line 36, in <module>
    ewmh = EWMH()
  File "/usr/lib/python3/dist-packages/ewmh.py", line 50, in __init__
    self.display = _display or display.Display()
  File "/usr/lib/python3/dist-packages/Xlib/display.py", line 80, in __init__
    self.display = _BaseDisplay(display)
  File "/usr/lib/python3/dist-packages/Xlib/display.py", line 62, in __init__
    display.Display.__init__(*(self, ) + args, **keys)
  File "/usr/lib/python3/dist-packages/Xlib/protocol/display.py", line 129, in __init__
    raise error.DisplayConnectionError(self.display_name, r.reason)
Xlib.error.DisplayConnectionError: Can't connect to display ":0": b'Invalid MIT-MAGIC-COOKIE-1 key'

[Reuben Thomas (rrt)]

I'm sorry, I don't have time to test non-LTS versions. If anyone else can help with this I'd be most grateful.

[rafael_henrique (rhsolive)]

It appears to be a problem with permissions in the Xauthority file. Giving read and write permissions to others into this file may solve the problem, but may decrease the security level.

[Reuben Thomas (rrt)]

I'm now using the LTS vivid X stack on my 14.04 machine and am getting this error, which appears to be caused by a python3-xlib bug: https://github.com/LiuLang/python3-xlib/issues/6

However, this bug is fixed in 15.04's python3-xlib 0.14+20091101-1ubuntu3. The date (17 Mar 2015) suggests it would have shipped with 15.04 (i.e. not be a later update), but I guess it could be.

Can anyone confirm they see this bug with 15.04 or later with up-to-date packages?

[Alain Rouet (alain-rouet)]

I can confirm that:
- I never got this error message on Ubuntu 15.04
- it only appeared, on Ubuntu 14.04, after updating to Vivid kernel and X stack
- installing "python3-xlib" from Vivid repository resolved the issue

[Waz (paviluf)]

I have the same error on Ubuntu 14.04 after updating to Vivid kernel and X.

[Waz (paviluf)]

I opened a bug for python-xlib

https://bugs.launchpad.net/ubuntu/+source/python-xlib/+bug/1482844

[Ed Guenter (edgue)]

Same here: upgraded to 14.04.4 today; and caffeine stops working with the errors listed above.

[Waz (paviluf)]

Reuben Thomas do you think you can fix this or it's python-xlib that have to be fixed ?

[Waz (paviluf)]

It seems that it will be fixed in python-xlib finally.
https://bugs.launchpad.net/ubuntu/+source/python-xlib/+bug/1482844

[a903user (a903user)]

I can confirm this bug in Ubuntu 14.04 after upgrade to the version 14.04.3 where is kernel 3.19 and x.org 1.17. Will be this bug fix in caffeine?

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Joseph Aczel (jaczel)]

Can confirm that on 14.04, installing the Vivid Vervet python3-xlib package will resolve the bug.

[a903user (a903user)]

I can also confirm this solution (upgrade python3-xlib). But it is not solution for a common user. They do not know how to do it.

Package python3-xlib in Ubuntu:

Ubuntu 14.04 - version (0.14+20091101-1ubuntu2)
Ubuntu 15.04 - version (0.14+20091101-1ubuntu3)

http://packages.ubuntu.com/search?suite=all&searchon=names&keywords=python3-xlib

[Peter Maciejko (corsseir)]

I also have this bug, when are you going to fix it?

[[e-mail] (n4rps-z)]

Hello!

This only seems to affect those who have upgraded to 14.04.3. It's not THEIR bug, so they're probably not going to 'fix' it.

I couldn't find version (0.14+20091101-1ubuntu3) in 32-bit, but here's a link to the amd64 version:

https://launchpad.net/ubuntu/vivid/amd64/python3-xlib/0.14+20091101-1ubuntu3

For me, going there asked me to download the .deb file. I Installed it using gdebi, rebooted, and caffeine now works as it should.

I consider myself a 'common user', and the whole process was considerably less than rocket science for me. Of course, YMMV...

[[e-mail] (n4rps-z)]

Hello!

Oops, wrong link. Don't see any way to delete or edit; perhaps someone who can will fix it to reflect the following:

http://mirrors.kernel.org/ubuntu/pool/universe/p/python-xlib/python3-xlib_0.14+20091101-1ubuntu2_all.deb

My apologies...

[[e-mail] (n4rps-z)]

Arrrrgh...

http://mirrors.kernel.org/ubuntu/pool/universe/p/python-xlib/python3-xlib_0.14+20091101-1ubuntu3_all.deb

[oriolpont (oriolpont)]

Even with these upgraded versions I keep getting:

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc0 in position 0: invalid start byte

Version 0.14+20091101-5 which is currently in debian unstable (https://packages.debian.org/sid/python3-xlib) solved this.

[kay (kay-diam)]

python3-xlib_0.14+20091101-1ubuntu3_all.deb didn't solve the issue. I receive:

Traceback (most recent call last):
  File "/usr/bin/caffeine", line 36, in <module>
    ewmh = EWMH()
  File "/usr/lib/python3/dist-packages/ewmh.py", line 50, in __init__
    self.display = _display or display.Display()
  File "/usr/lib/python3/dist-packages/Xlib/display.py", line 80, in __init__
    self.display = _BaseDisplay(display)
  File "/usr/lib/python3/dist-packages/Xlib/display.py", line 62, in __init__
    display.Display.__init__(*(self, ) + args, **keys)
  File "/usr/lib/python3/dist-packages/Xlib/protocol/display.py", line 129, in __init__
    raise error.DisplayConnectionError(self.display_name, r.reason)
Xlib.error.DisplayConnectionError: Can't connect to display ":0": b'Invalid MIT-MAGIC-COOKIE-1 key'

Old python3-xlib_0.14+20091101-1ubuntu2_all.deb returns:

Traceback (most recent call last):
  File "/usr/bin/caffeine", line 36, in <module>
    ewmh = EWMH()
  File "/usr/lib/python3/dist-packages/ewmh.py", line 50, in __init__
    self.display = _display or display.Display()
  File "/usr/lib/python3/dist-packages/Xlib/display.py", line 80, in __init__
    self.display = _BaseDisplay(display)
  File "/usr/lib/python3/dist-packages/Xlib/display.py", line 62, in __init__
    display.Display.__init__(*(self, ) + args, **keys)
  File "/usr/lib/python3/dist-packages/Xlib/protocol/display.py", line 129, in __init__
    raise error.DisplayConnectionError(self.display_name, r.reason)
Xlib.error.DisplayConnectionError: Can't connect to display ":0": b'No protocol specified\n'

ubuntu 14.04 lts with 3.19.0-30-generic kernel from vivid and xserver-xorg-lts-vivid 1:7.7+7ubuntu3~trusty1

[kay (kay-diam)]

python3-xlib_0.14+20091101-5_all.deb doesn't fix the issue too:

Traceback (most recent call last):
  File "/usr/bin/caffeine", line 36, in <module>
    ewmh = EWMH()
  File "/usr/lib/python3/dist-packages/ewmh.py", line 50, in __init__
    self.display = _display or display.Display()
  File "/usr/lib/python3/dist-packages/Xlib/display.py", line 80, in __init__
    self.display = _BaseDisplay(display)
  File "/usr/lib/python3/dist-packages/Xlib/display.py", line 62, in __init__
    display.Display.__init__(*(self, ) + args, **keys)
  File "/usr/lib/python3/dist-packages/Xlib/protocol/display.py", line 129, in __init__
    raise error.DisplayConnectionError(self.display_name, r.reason)
Xlib.error.DisplayConnectionError: Can't connect to display ":0": b'Invalid MIT-MAGIC-COOKIE-1 key'

[kay (kay-diam)]

rm .Xauthority and relogin has solved the issue.