Solution to error in installing native gem on windows.
gem install json Fetching: json-1.8.1.gem (100%) Temporarily enhancing PATH to include DevKit... Building native extensions. This could take a while... ERROR: Error installing json: ERROR: Failed to build gem native extension. C:/Ruby193/bin/ruby.exe -r ./siteconf20140809-24288-wfgqsd.rb extconf.rb creating Makefile make clean Makefile:165: *** target pattern contains no `%'. Stop. make Makefile:165: *** target pattern contains no `%'. Stop. make failed, exit code 2 Gem files will remain installed in C:/Ruby193/lib/ruby/gems/1.9.1/gems/json-1.8.1 for inspection. Results logged to C:/Ruby193/lib/ruby/gems/1.9.1/extensions/x86-mingw32/1.9.1/json-1.8.1/gem_make.out
