I can't find the docs on what the options hash should include, but passing a string causes a core dump.

Demo:

irb(main):002:0> require "sqlite3"
=> true
irb(main):003:0> SQLite3::Database.new("some.db", "w+")
(irb):3: [BUG] Segmentation fault
ruby 1.8.7 (2010-08-16 patchlevel 302) [i686-linux]

zsh: abort (core dumped)  irb
~/w/wiki/burndown % dpkg -l | grep sqlite3 | grep ruby
ii  libsqlite3-ruby                       1.3.1-2                                    SQLite3 interface for Ruby
ii  libsqlite3-ruby1.8                    1.3.1-2                                    SQLite3 interface for Ruby 1.8