`ffi_libraries': no library specif ied (LoadError)

Getting the following error:

C:\p4\spgp4\spg\beaver>jruby -S buildr -v --trace
c:/jruby-1.5.0.RC1/lib/ruby/site_ruby/shared/ffi/library.rb:46:in `ffi_libraries': no library specif
ied (LoadError)
from c:/jruby-1.5.0.RC1/lib/ruby/site_ruby/shared/ffi/library.rb:96:in `attach_function'
from c:/jruby-1.5.0.RC1/lib/ruby/gems/1.8/gems/buildr-1.3.5-java/lib/buildr/core/util.rb:410

from c:/jruby-1.5.0.RC1/lib/ruby/gems/1.8/gems/buildr-1.3.5-java/lib/buildr/core/util.rb:31:
in `require'
from c:/jruby-1.5.0.RC1/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from c:/jruby-1.5.0.RC1/lib/ruby/gems/1.8/gems/buildr-1.3.5-java/lib/buildr/core/common.rb:1
8
from c:/jruby-1.5.0.RC1/lib/ruby/gems/1.8/gems/buildr-1.3.5-java/lib/buildr/core/common.rb:3
1:in `require'
from c:/jruby-1.5.0.RC1/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from c:/jruby-1.5.0.RC1/lib/ruby/gems/1.8/gems/buildr-1.3.5-java/lib/buildr/core.rb:22
from c:/jruby-1.5.0.RC1/lib/ruby/gems/1.8/gems/buildr-1.3.5-java/lib/buildr/core.rb:31:in `r
equire'
from c:/jruby-1.5.0.RC1/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from c:/jruby-1.5.0.RC1/lib/ruby/gems/1.8/gems/buildr-1.3.5-java/lib/buildr.rb:20
from c:/jruby-1.5.0.RC1/lib/ruby/gems/1.8/gems/buildr-1.3.5-java/lib/buildr.rb:31:in `requir
e'
from c:/jruby-1.5.0.RC1/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from C:/jruby-1.5.0.RC1/lib/ruby/gems/1.8/gems/buildr-1.3.5-java/bin/buildr:18
from C:/jruby-1.5.0.RC1/lib/ruby/gems/1.8/gems/buildr-1.3.5-java/bin/buildr:19:in `load'
from c:/jruby-1.5.0.RC1/bin/buildr:19

Installed gems:

C:\p4\spgp4\spg\beaver>jruby -S gem list

• • • LOCAL GEMS ***

Antwrap (0.7.0)
archive-tar-minitar (0.5.2)
builder (2.1.2)
buildr (1.3.5)
columnize (0.3.1)
ffi (0.6.3)
highline (1.5.1)
hoe (2.3.3)
jruby-openssl (0.5.2)
json_pure (1.4.0)
net-sftp (2.0.2)
net-ssh (2.0.15)
rake (0.8.7)
rspec (1.3.0, 1.2.9, 1.2.8)
ruby-debug (0.10.3)
ruby-debug-base (0.10.3.1)
rubyforge (2.0.3, 1.0.5)
rubyzip (0.9.1)
sources (0.0.1)
xml-simple (1.0.12)