Jruby Windows 7 win32-api build error

undefined_SafeStringValue

$ gem install win32-api --version '~> 1.4.8'
Temporarily enhancing PATH to include DevKit...
Building native extensions.  This could take a while...
ERROR:  Error installing win32-api:
        ERROR: Failed to build gem native extension.

        c:/jruby/jruby-1.6.7/bin/jruby.exe extconf.rb
WARNING: JRuby does not support native extensions or the `mkmf' library very wel
l.
Check http://kenai.com/projects/jruby/pages/Home for alternatives.
checking for strncpy_s()... no
creating Makefile

make
gcc -I. -I. -Ic:/jruby/jruby-1.6.7/lib/native/include/ruby -I.  -fno-omit-frame-pointer -fno-strict-aliasing  -fexceptions    -m32 -march=native -mtune=native -c win32/api.c
gcc -shared  -s -o api.dll api.o -L"." -L"/jruby/jruby-1.6.7/lib" -Lc:/jruby/jruby-1.6.7/lib/native/i386-Windows -ljruby-cext -Wl,--enable-auto-image-base,--enable-auto-import  -m32 -march=native -mtune=native
api.o:api.c:(.text+0x66c): undefined reference to `SafeStringValue'
api.o:api.c:(.text+0x677): undefined reference to `SafeStringValue'
api.o:api.c:(.text+0x8e5): undefined reference to `SafeStringValue'
api.o:api.c:(.text+0xa28): undefined reference to `SafeStringValue'
api.o:api.c:(.text+0xce0): undefined reference to `SafeStringValue'
api.o:api.c:(.text+0xe23): more undefined references to `SafeStringValue' follow

api.o:api.c:(.text+0x1171): undefined reference to `rb_str_modify'
api.o:api.c:(.text+0x3cc0): undefined reference to `rb_str_modify'
collect2: ld returned 1 exit status
make: *** [api.dll] Error 1


Gem files will remain installed in c:/jruby/jruby-1.6.7/lib/ruby/gems/1.8/gems/win32-api-1.4.8 for inspection.
Results logged to c:/jruby/jruby-1.6.7/lib/ruby/gems/1.8/gems/win32-api-1.4.8/ext/gem_make.out