Here is the backtrace with gdb:
$ gdb lyx
GNU gdb 19991004
Copyright 1998 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-redhat-linux"...
(gdb) run
Starting program: /local/software/LyX/lyx-devel/src/lyx
Running without personal LyX directory.
Warning: language `default' not recognized!
Setting language to `english'.
Program received signal SIGSEGV, Segmentation fault.
BufferView::buffer (this=0xf1) at BufferView.C:43
43 return pimpl_->buffer_;
(gdb) bt
#0 BufferView::buffer (this=0xf1) at BufferView.C:43
#1 0x8177114 in InsetBibKey::callback (this=0x837a8c0, form=0x837a500, data=1)
at insetbib.C:102
#2 0x8176e28 in bibitem_cb (data=1) at insetbib.C:42
#3 0x82051c4 in fl_object_qread () at slot.cc:80
#4 0x8203d6e in fl_check_forms () at slot.cc:80
#5 0x81aa968 in GUIRunTime::runTime () at GUIRunTime.C:79
#6 0x80ca17d in LyXGUI::runTime (this=0x82e9880) at lyx_gui.C:393
#7 0x80cbe68 in LyX::LyX (this=0xbffffb4c, argc=0xbffffb70, argv=0xbffffbb4)
at ../src/lyx_main.C:167
#8 0x81079a8 in main (argc=1, argv=0xbffffbb4) at ../src/main.C:40
