$ gdb `which ruby`
GNU gdb 6.3.50-20050815 (Apple version gdb-477) (Sun Apr 30 20:06:22 GMT 2006)
Copyright 2004 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 "powerpc-apple-darwin"...Reading symbols for shared libraries ... done

(gdb) run -Ilib test/test_parse_tree.rb -n /test_parse_tree_for_string/
Starting program: /usr/local/bin/ruby -Ilib test/test_parse_tree.rb -n /test_parse_tree_for_string/
Reading symbols for shared libraries .. done
Reading symbols for shared libraries . done
Reading symbols for shared libraries . done
Reading symbols for shared libraries ... done
Reading symbols for shared libraries . done
Reading symbols for shared libraries . done
Reading symbols for shared libraries . done
Reading symbols for shared libraries . done
Loaded suite test/test_parse_tree
Started

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_PROTECTION_FAILURE at address: 0x00000001
st_lookup (table=0x1, key=3943, value=0xbffecf98) at st.c:245
245         hash_val = do_hash(key, table);
(gdb) run -Ilib test/test_parse_tree.rb -n /test_parse_tree_for_string/
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Starting program: /usr/local/bin/ruby -Ilib test/test_parse_tree.rb -n /test_parse_tree_for_string/
Reading symbols for shared libraries + done
nuking /Users/drbrain/.ruby_inline
Reading symbols for shared libraries + done
BFD: BFD 2.16.91 20050815 internal error, aborting at /SourceCache/gdb/gdb-477/src/bfd/cache.c line 517 in bfd_cache_lookup_worker

BFD: Please report this bug.