Comment 7 for bug 921995

I have the same problem described. In my case, none of the display managers will load because all of them fail with a segfault in libgio-2.0.so.0.3000.0. I have tried purging
all of the dm's and starting anew as well as changing lightdm config, but I still can't use a graphical display because of that one file that causes a problem in every
login program I use. I have also tried reinstalling the package that contains the .so file that is segfaulting (libglib2.0-0), but the file does not change at all.
I have the packages you describe installed. I am not sure how I can get my computer to function correctly.

However, something interesting is happening in my logs that I think may be related to this failure, or perhaps even the cause of the segfault. My ~/.xsession-errors log
file gives, in about 100 very specific lines detailing what exactly it can't load, the general impression that it can't connect to DBus. I am not sure if this is a common
error that happens when there is an X problem, or one that is a symptom of a more specific problem. I will upload my log files, see if you can take a look, and maybe tell
me how to temporarily at least how to get a working graphical environment.