Ok, I must confess I have not much experience in using gdb, but here is what I 
get:

$ gdb ruby

(gdb) run -e "require 'Qt'"
Starting program: /usr/bin/ruby -e "require 'Qt'"
(no debugging symbols found)...(no debugging symbols found)...(no debugging 
symbols found)...(no debugging symbols found)...(no debugging symbols 
found)...(no debugging symbols found)...(no debugging symbols found)...(no 
debugging symbols found)...(no debugging symbols found)...(no debugging 
symbols found)...(no debugging symbols found)...(no debugging symbols 
found)...(no debugging symbols found)...(no debugging symbols found)...(no 
debugging symbols found)...(no debugging symbols found)...(no debugging 
symbols found)...(no debugging symbols found)...(no debugging symbols 
found)...(no debugging symbols found)...(no debugging symbols found)...(no 
debugging symbols found)...(no debugging symbols found)...[Thread debugging 
using libthread_db enabled]
[New Thread 16384 (LWP 20408)]
(no debugging symbols found)...(no debugging symbols found)...(no debugging 
symbols found)...(no debugging symbols found)...(no debugging symbols 
found)...(no debugging symbols found)...(no debugging symbols found)...
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 16384 (LWP 20408)]
0x40fd86f9 in __pthread_unlock () from /lib/libpthread.so.0
(gdb) 
(gdb) backtrace
#0  0x40fd86f9 in __pthread_unlock () from /lib/libpthread.so.0
#1  0x40fd5d15 in pthread_mutex_unlock () from /lib/libpthread.so.0
#2  0x40242a5b in _dl_open () from /lib/libc.so.6
#3  0x400ebe8b in dlopen_doit () from /lib/libdl.so.2
#4  0x4000ad76 in _dl_catch_error_internal () from /lib/ld-linux.so.2
#5  0x400ec276 in _dlerror_run () from /lib/libdl.so.2
#6  0x400ebed4 in dlopen@@GLIBC_2.1 () from /lib/libdl.so.2
#7  0x40041e07 in dln_load () from /usr/lib/libruby.so.1.8
#8  0x4005b48e in rb_require_safe () from /usr/lib/libruby.so.1.8
#9  0x0000002e in ?? ()
#10 0x00000000 in ?? ()
#11 0x00000000 in ?? ()
#12 0x00000000 in ?? ()
#13 0x00000000 in ?? ()
#14 0x08079518 in ?? ()
#15 0xbfffe318 in ?? ()
#16 0xbfffe31c in ?? ()
#17 0x40289100 in ?? ()
#18 0x00000000 in ?? ()
#19 0x00000004 in ?? ()
#20 0x00000000 in ?? ()
#21 0x402890b0 in ?? ()
#22 0x40289060 in ?? ()
---Type <return> to continue, or q <return> to quit---
#23 0x402890b0 in ?? ()
#24 0x400da214 in __JCR_LIST__ () from /usr/lib/libruby.so.1.8
#25 0x402989e8 in ?? ()
#26 0x4005b690 in rb_require () from /usr/lib/libruby.so.1.8
Previous frame inner to this frame (corrupt stack?)
(gdb) 

If this still isn't what you need, let me know.

regards,
jochen


Am Dienstag 13 Juli 2004 21:04 schrieb Alexander Kellett:
> start gdb with:
>    gdb ruby
> then try
>    run -e "require 'Qt'"
> can't test... don't have a working x11 installation :s
> but it should work if i remember gdb correctly :P
> Alex
>
> On Wed, Jul 14, 2004 at 03:41:56AM +0900, Jochen Immend?rfer wrote:
> > hm.. I'm sorry to say so, but I don't now how to do this. If you tell me
> > what I exactly have to do, I'll give my best ;)
> >
> > > can you run in gdb?
> > > backtrace is reallllly needed
> > >
> > > Alex