[ruby-core:25284] Segfault in parser (list_concat_gen)

Sorry for not submitting a patch, but I'm probably too dumb to work
out the cause.

Problem:
========
Got latest ruby, fired up rails app, segfault - every time, same place

Version:
========
http://svn.ruby-lang.org/repos/ruby/trunk, Rev : 24738
Built with CFLAGS=-g3, CXXFLAGS=-g3 for GDB session (below)
(Ubuntu Studio, Karmic Alpha 4, amd64

GDB session:
===========
Starting program: /usr/local/bin/ruby ./script/server -e production

---------- (snip) -----------
=> Booting WEBrick
=> Rails 2.3.3 application starting on http://0.0.0.0:3000
---------- (snip) -----------
Program received signal SIGSEGV, Segmentation fault.
0x000000000046a099 in list_concat_gen (parser=0x221c6a0, head=0x15388a0, tail=0x1537888) at parse.y:7785
7785	    last->nd_next = tail;
(gdb) inspect last
$1 = (NODE *) 0x1
(gdb) inspect *head
$10 = {flags = 5454364, nd_file = 0x0, u1 = {node = 0x15388f0, id = 22251760, value = 22251760, cfunc = 0x15388f0, tbl = 0x15388f0}, 
  u2 = {node = 0x1538445, id = 22250565, argc = 22250565, value = 22250565}, u3 = {node = 0x1538788, id = 22251400, state = 22251400, 
    entry = 0x1538788, cnt = 22251400, value = 22251400}}
(gdb) bt
#0  0x000000000046a099 in list_concat_gen (parser=0x221c6a0, head=0x15388a0, tail=0x1537888) at parse.y:7785
#1  0x000000000046a3f1 in literal_concat_gen (parser=0x221c6a0, head=0x15388a0, tail=0x1537888) at parse.y:7857
#2  0x000000000045f5b5 in ruby_yyparse (parser=0x221c6a0) at parse.y:3770
#3  0x000000000046202d in yycompile0 (arg=35767968, tracing=0) at parse.y:5004
#4  0x000000000052943a in ruby_suppress_tracing (func=0x461f0b <yycompile0>, arg=35767968, always=2) at thread.c:3862
#5  0x00000000004621b8 in yycompile (parser=0x221c6a0, 
    f=0x221aad0 "/usr/local/lib/ruby/gems/1.9.1/gems/ruby-openid-2.1.7/lib/openid/consumer/idres.rb", line=1) at parse.y:5030
#6  0x0000000000462726 in rb_parser_compile_file (vparser=23036880, 
---------- (snip) -----------


Additional info:
===============
If there is anything I could do to help nail this quickly let me know.
I'll keep the session on and be on standby. 

Cheers.

-- 
Cezary Bagiナгki