I get the following when I try to compile on windows - any
suggestions?  Not sure what srcdir should be or where I should set it.

========================================================================

C:\ffi>gem install ffi-0.1.0.gem
Building native extensions.  This could take a while...
ERROR:  Error installing ffi-0.1.0.gem:
        ERROR: Failed to build gem native extension.

C:/ruby/bin/ruby.exe extconf.rb install ffi-0.1.0.gem
creating Makefile

nmake

Microsoft (R) Program Maintenance Utility Version 9.00.30729.01
Copyright (C) Microsoft Corporation.  All rights reserved.

makefile(182) : fatal error U1052: file '$(srcdir)/ffi.mk' not found
Stop.


Gem files will remain installed in C:/ruby/lib/ruby/gems/1.8/gems/
ffi-0.1.0 for inspection.
Results logged to C:/ruby/lib/ruby/gems/1.8/gems/ffi-0.1.0/ext/
gem_make.out