I don't know if anybody else is seeing this, but on a build of 15098 I'm 
seeing the following failures:

test_m17n.rb ....bootstraptest.tmp.rb:3: [BUG] Segmentation fault
ruby 1.9.0 (2008-01-18 revision 0) [i686-linux]

-- control frame ----------
c:0004 p:---- s:0011 b:0011 l:000010 d:000010 CFUNC  :%
c:0003 p:0026 s:0007 b:0006 l:000005 d:000005 TOP    bootstraptest.tmp.rb:3
c:0002 p:---- s:0004 b:0004 l:000003 d:000003 FINISH :inherited
c:0001 p:0000 s:0002 b:0002 l:000001 d:000001 TOP    <dummy toplevel>:17
---------------------------
DBG> : "bootstraptest.tmp.rb:3:in `<main>'"
-- backtrace of native function call (Processed by addr2line) --
/home/rubys/svn/ruby/compile.c:3087
/home/rubys/svn/ruby/io.c:4242
/home/rubys/svn/ruby/io.c:4243
/home/rubys/svn/ruby/./include/ruby/ruby.h:918
??:0
/home/rubys/svn/ruby/vm.inc:1014
/home/rubys/svn/ruby/vm.inc:651
/home/rubys/svn/ruby/eval.c:1864
/home/rubys/svn/ruby/eval.c:2031
/home/rubys/svn/ruby/iseq.c:947
/home/rubys/svn/ruby/insns.def:1796
/home/rubys/svn/ruby/compile.c:3242
/home/rubys/svn/ruby/compile.c:1474
/home/rubys/svn/ruby/compile.c:2850
/home/rubys/svn/ruby/compile.c:2791
/home/rubys/svn/ruby/marshal.c:1046
/home/rubys/svn/ruby/numeric.c:873
/home/rubys/svn/ruby/eval_safe.c:75
??:0
/home/rubys/svn/ruby/eval.c:2092
-------------------------------------------------------
E........bootstraptest.tmp.rb:5: [BUG] Segmentation fault
ruby 1.9.0 (2008-01-18 revision 0) [i686-linux]

-- control frame ----------
c:0004 p:---- s:0013 b:0013 l:000012 d:000012 CFUNC  :upto
c:0003 p:0035 s:0009 b:0008 l:000007 d:000007 TOP    bootstraptest.tmp.rb:5
c:0002 p:---- s:0004 b:0004 l:000003 d:000003 FINISH :inherited
c:0001 p:0000 s:0002 b:0002 l:000001 d:000001 TOP    <dummy toplevel>:17
---------------------------
DBG> : "bootstraptest.tmp.rb:5:in `<main>'"
-- backtrace of native function call (Processed by addr2line) --
/home/rubys/svn/ruby/compile.c:3087
/home/rubys/svn/ruby/io.c:4242
/home/rubys/svn/ruby/io.c:4243
/home/rubys/svn/ruby/./include/ruby/ruby.h:918
??:0
/home/rubys/svn/ruby/vm.inc:1014
/home/rubys/svn/ruby/vm.inc:651
/home/rubys/svn/ruby/eval.c:1864
/home/rubys/svn/ruby/eval.c:2031
/home/rubys/svn/ruby/thread.c:2868
/home/rubys/svn/ruby/file.c:4216
/home/rubys/svn/ruby/compile.c:3242
/home/rubys/svn/ruby/compile.c:1194
/home/rubys/svn/ruby/compile.c:2850
/home/rubys/svn/ruby/compile.c:2791
/home/rubys/svn/ruby/marshal.c:1046
/home/rubys/svn/ruby/numeric.c:873
/home/rubys/svn/ruby/eval_safe.c:75
??:0
/home/rubys/svn/ruby/eval.c:2092
-------------------------------------------------------
E..bootstraptest.tmp.rb:4: [BUG] Segmentation fault
ruby 1.9.0 (2008-01-18 revision 0) [i686-linux]

-- control frame ----------
c:0004 p:---- s:0013 b:0013 l:000012 d:000012 CFUNC  :casecmp
c:0003 p:0035 s:0009 b:0008 l:000007 d:000007 TOP    bootstraptest.tmp.rb:4
c:0002 p:---- s:0004 b:0004 l:000003 d:000003 FINISH :inherited
c:0001 p:0000 s:0002 b:0002 l:000001 d:000001 TOP    <dummy toplevel>:17
---------------------------
DBG> : "bootstraptest.tmp.rb:4:in `<main>'"
-- backtrace of native function call (Processed by addr2line) --
/home/rubys/svn/ruby/compile.c:3087
/home/rubys/svn/ruby/io.c:4242
/home/rubys/svn/ruby/io.c:4243
/home/rubys/svn/ruby/./include/ruby/ruby.h:918
??:0
/home/rubys/svn/ruby/eval_safe.c:63
/home/rubys/svn/ruby/thread.c:1409
/home/rubys/svn/ruby/compile.c:3242
/home/rubys/svn/ruby/compile.c:1194
/home/rubys/svn/ruby/compile.c:2850
/home/rubys/svn/ruby/compile.c:2791
/home/rubys/svn/ruby/marshal.c:1046
/home/rubys/svn/ruby/numeric.c:873
/home/rubys/svn/ruby/eval_safe.c:75
??:0
/home/rubys/svn/ruby/eval.c:2092
-------------------------------------------------------