title: Ruby on Rails - how to install capybara gem in Windows?
body: <p>Please help me to install capybara gem in Windows.</p>
  
  <pre><code>&gt;gem install capybara
  Temporarily enhancing PATH to include DevKit...
  Building native extensions.  This could take a while...
  ERROR:  Error installing capybara:
          ERROR: Failed to build gem native extension.
  
          C:/Ruby193/bin/ruby.exe extconf.rb
  checking for ffi.h... no
  checking for ffi.h in /usr/local/include,/usr/include/ffi... no
  checking for rb_thread_blocking_region()... yes
  checking for ruby_native_thread_p()... yes
  checking for rb_thread_call_with_gvl()... yes
  creating extconf.h
  creating Makefile
  
  make
  generating ffi_c-i386-mingw32.def
  Configuring libffi
  configure: WARNING: cache variable lt_cv_path_LD contains a newline
  configure: WARNING: cache variable lt_cv_path_LD contains a newline
  make -C "/c/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5/ext/ffi_c/libffi-i386-mingw32"
  make[1]: Entering directory `/c/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5/ext/ffi_c/libffi-i386-mingw32'
  Makefile:318: *** missing separator.  Stop.
  make[1]: Leaving directory `/c/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5/ext/ffi_c/libffi-i386-mingw32'
  make: *** ["/c/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5/ext/ffi_c/libffi-i386-mingw32"/.libs/libffi_convenience.a] Error 2
  
  
  Gem files will remain installed in C:/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5 for inspection.
  Results logged to C:/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5/ext/ffi_c/gem_make.out
  </code></pre>
  
  <p>I already have downloaded and installed some 1,7 GB "QT" thing as my colleagues advised, with no effect.</p>
  
  <p><strong>Update:</strong></p>
  
  <pre><code>&gt;gem install ffi
  Temporarily enhancing PATH to include DevKit...
  Building native extensions.  This could take a while...
  ERROR:  Error installing ffi:
          ERROR: Failed to build gem native extension.
  
          C:/Ruby193/bin/ruby.exe extconf.rb
  checking for ffi.h... no
  checking for ffi.h in /usr/local/include,/usr/include/ffi... no
  checking for rb_thread_blocking_region()... yes
  checking for ruby_native_thread_p()... yes
  checking for rb_thread_call_with_gvl()... yes
  creating extconf.h
  creating Makefile
  
  make
  generating ffi_c-i386-mingw32.def
  Configuring libffi
  configure: WARNING: cache variable lt_cv_path_LD contains a newline
  configure: WARNING: cache variable lt_cv_path_LD contains a newline
  make -C "/c/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5/ext/ffi_c/libffi-i386-mingw32"
  make[1]: Entering directory `/c/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5/ext/ffi_c/libffi-i386-min
  gw32'
  Makefile:318: *** missing separator.  Stop.
  make[1]: Leaving directory `/c/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5/ext/ffi_c/libffi-i386-ming
  w32'
  make: *** ["/c/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5/ext/ffi_c/libffi-i386-mingw32"/.libs/libff
  i_convenience.a] Error 2
  
  
  Gem files will remain installed in C:/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5 for inspection.
  Results logged to C:/Ruby193/lib/ruby/gems/1.9.1/gems/ffi-1.1.5/ext/ffi_c/gem_make.out
  </code></pre>