Cannot install JSON gem in rails using windows

Question

I am doing a bundle install and all of the gems work fine except JSON when it get to the JSON gem I receive this error.

Installing json (1.6.1) with native extensions c:/Ruby192/lib/ruby/site_ruby/1.9.1/rubygems/installer.rb:55
    2:in `rescue in block in build_extensions': ERROR: Failed to build gem native extension. (Gem::Installer::E
    xtensionBuildError)

            c:/Ruby192/bin/ruby.exe extconf.rb
    checking for re.h... *** extconf.rb failed ***
    Could not create Makefile due to some reason, probably lack of
    necessary libraries and/or headers.  Check the mkmf.log file for more
    details.  You may need configuration options.

Any idea on what could be causing this error?

Answer 1

You are working with Windows, so the RubyInstaller Development Kit may help you: http://rubyinstaller.org/add-ons/devkit/

The devkit installs a C-compiler (and some other stuff) to compile C-written parts.

Install it and try again to install the gem - perhaps with option --platform=ruby.

Details can be found at https://github.com/oneclick/rubyinstaller/wiki/Development-Kit

Answer 2

That's because this gem using a piece of code written on C. For working properly you need c compiler installed on your machine. As a way, try to use json_pure written on pure Ruby