[xmonad] Segfault

[Don Stewart]

jim:
> At Wed, 1 Apr 2009 08:57:32 +0100 (BST),
> Jim Burton wrote:
> > 
> > At Tue, 31 Mar 2009 18:23:49 -0500,
> > Spencer Janssen wrote:
> > >
> > > On Tue, Mar 31, 2009 at 07:50:29AM +0100, Jim Burton wrote:
> > > > Hi, I'm using xmonad 0.8.1, GHC 6.10, Ubuntu intrepid, and every now and
> > > > then I get an X error immediately after logging in and am bounced back to
> > > > the login screen. Logging in again normally works fine. Here is
> > > > .xsession-errors from one of those occasions:
> > > >
> > [snip]
> > > > The line .xsession-errors refers to is the last one, which launches
> > > > xmonad. What's going on?
> > > >
> > > > Thanks,
> > > >
> > > >
> > > > --
> > > > Jim Burton
> > >
> > > We need information to see what is going on.  The most likely problem is a
> > > miscompiled xmonad, try cleaning, rebuilding, and reinstalling xmonad and
> > > contrib.  Finally, execute "xmonad --recompile".
> > >
> > 
> > Thanks for your reply. I already rebuilt but will try xmonad
> > --recompile.
> > 
> > > If the problem persists, try to get a stack trace.
> > >
> > 
> > How do I do this?
> >
> 
> Can anyone tell me how to get a stack trace when xmonad crashes or
> otherwise diagnose my problem? The problem does indeed persist and I
> don't know if it's a known bug etc.
> 

The main way is to attach gdb to the core, and we'll see if it is in
Haskell code (meaning a GHC bug or FFI binding error), or in X11 code (X
bug?). 

The most important thing is to list GHC versions, X11 versions, Haskell
library versions, and to ensure it is clean build.

Then, narrow down the extensions you're using to find the smallest set
that produces the error.