> > While I never install ffi this way, jruby+bundler on Win7 32bit with JRuby 
> > 1.7.0 ended up in Wile E. flames trying to build the C ext due to my 
> > scheming: 
> >
> > C:\Users\Jon\Downloads\temp\ffi-java>type Gemfile 
> > source :rubygems 
> > gem 'ffi', '1.2.0.pre6', :platforms => :jruby 
> >
> > C:\Users\Jon\Downloads\temp\ffi-java>bundle install 
> > Fetching gem metadata from http://rubygems.org/........... 
> > Fetching gem metadata from http://rubygems.org/.. 
> > Installing ffi (1.2.0.pre6) with native extensions 
> > Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native 
> > extension. 

> 
>  
> Hmm.  When installing on something that is not MRI, extconf.rb generates a 
> dummy Makefile.  I suspect on win32, the dummy Makefile isn't quite 
> correct.  Can you investigate this one a bit more (look right at the bottom 
> of ext/ext_c/extconf.rb)?  It could be something as simple as \r\n vs \n 
> line termination.
> 
> I can continue to publish the ffi-java gem, but, I want to get rid of it in 
> the long term.

Likely just need this tweak at extconf.rb:59

-  File.open("Makefile", "w") do |mf|
+  File.open("Makefile", "wb") do |mf|

I'll try it out a bit later.