title: Errors Installing the gem wdm in cygwin
body: <p>I keep getting this error while installing the gem wdm from inside cygwin. Does anybody had the same issue and know now to fix it. Thanks. (I am Trying to install Guard gem)</p>
  
  <pre><code>$ gem install wdm
  Building native extensions.  This could take a while...
  ERROR:  Error installing wdm:
  ERROR: Failed to build gem native extension.
  
      /usr/bin/ruby.exe extconf.rb
  checking for main() in -lkernel32... yes
  checking for windows.h... yes
  checking for ruby.h... yes
  checking for HAVE_RUBY_ENCODING_H... yes
  creating Makefile
  
  make
  gcc -I. -I/usr/include/ruby-1.9.1/i386-cygwin -I/usr/include/ruby-1.9.1/ruby/backward -I/usr/include/ruby-1.9.1 -I. -DHAVE_WINDOWS_H -DHAVE_RUBY_H -DHAVE_CONST_HAVE_RUBY_ENCODING_H    -ggdb -O2 -pipe   -fno-strict-aliasing   -o entry.o -c entry.c
  gcc -I. -I/usr/include/ruby-1.9.1/i386-cygwin -I/usr/include/ruby-1.9.1/ruby/backward -I/usr/include/ruby-1.9.1 -I. -DHAVE_WINDOWS_H -DHAVE_RUBY_H -DHAVE_CONST_HAVE_RUBY_ENCODING_H    -ggdb -O2 -pipe   -fno-strict-aliasing   -o memory.o -c memory.c
  gcc -I. -I/usr/include/ruby-1.9.1/i386-cygwin -I/usr/include/ruby-1.9.1/ruby/backward -I/usr/include/ruby-1.9.1 -I. -DHAVE_WINDOWS_H -DHAVE_RUBY_H -DHAVE_CONST_HAVE_RUBY_ENCODING_H    -ggdb -O2 -pipe   -fno-strict-aliasing   -o monitor.o -c monitor.c
  gcc -I. -I/usr/include/ruby-1.9.1/i386-cygwin -I/usr/include/ruby-1.9.1/ruby/backward -I/usr/include/ruby-1.9.1 -I. -DHAVE_WINDOWS_H -DHAVE_RUBY_H -DHAVE_CONST_HAVE_RUBY_ENCODING_H    -ggdb -O2 -pipe   -fno-strict-aliasing   -o queue.o -c queue.c
  gcc -I. -I/usr/include/ruby-1.9.1/i386-cygwin -I/usr/include/ruby-1.9.1/ruby/backward -I/usr/include/ruby-1.9.1 -I. -DHAVE_WINDOWS_H -DHAVE_RUBY_H -DHAVE_CONST_HAVE_RUBY_ENCODING_H    -ggdb -O2 -pipe   -fno-strict-aliasing   -o rb_change.o -c rb_change.c
  rb_change.c: In function ‘extract_absolute_path_from_notification’:
  rb_change.c:47:16: error: ‘_MAX_FNAME’ undeclared (first use in this function)
  rb_change.c:47:16: note: each undeclared identifier is reported only once for each function it appears in
  rb_change.c:47:33: error: ‘_MAX_EXT’ undeclared (first use in this function)
  Makefile:206: recipe for target `rb_change.o' failed
  make: *** [rb_change.o] Error 1
  
  Gem files will remain installed in /usr/lib/ruby/gems/1.9.1/gems/wdm-0.1.0 for inspection.
  Results logged to /usr/lib/ruby/gems/1.9.1/gems/wdm-0.1.0/ext/wdm/gem_make.out
  </code></pre>