Re: networkmanager causes gnome to not be able to open any programs

[Dan Williams <dcbw redhat com>]

On Wed, 2008-10-29 at 01:56 -0700, Xamindar wrote:
> I have been having this problem for a while now and it has seemed 
> random. All of a sudden I can't open any more programs, nothing happens. 
> If I try to open a program in a console I get something like:
> 
> gedit
> No protocol specified
> Cannot open display:
> Run 'gedit --help' to see a full list of available command line options.
> 
> I check the display variable and it looks fine. I finally narrowed it 
> down to something with networkmanager. I will be fine until I switch 
> networks in networkmanager. If networkmanager always stays on the same 
> network I am fine, but if I dare change networks I am then forced to 
> kill X and re-log back in to be able to open anything new.
> 
> What is causing this? Has anyone else experienced it?

You have either (a) not set a persistent hostname for your machine, or
(b) your distro doesn't have an X11 that handles hostname changes
gracefully.

The problem is that Xauth (brokenly) relies on a hostname at the time
you start X, and if that hostname ever changes, you can't open programs.
Fedora has been shipping a workaround for some time that simply allows
all Unix domain socket connections to the X server, because those
connections are already guaranteed to be local.  Suse ships something
different that achieves the same purpose.

Dan