Error installing the json gem on Windows - ruby-on-rails

Question

I am new to ruby on rails, I am trying to get my first project working with git and heroku. I am following the tutorial by Michael Hartl. I was originally trying to
git push heroku master
but I dont have a GemFile.lock, so I have been trying bundle installs and bundle updates but nothing works because I dont have the json native gem.
bundle update
this is the command that reuturned this error, its not the whole error i left out all the gems i already have
Installing json (1.7.3) with native extensions
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
"C:/Program Files/ruby-1.9.3/bin/ruby.exe" extconf.rb
creating Makefile
make
Makefile:160: warning: overriding commands for target `C:/Program'
Makefile:153: warning: ignoring old commands for target `C:/Program'
C:/Program Files/ruby-1.9.3/bin/ruby -e "puts 'EXPORTS', 'Init_parser'" > parser-i386
mingw32.def
/bin/sh: C:/Program: No such file or directory
make: *** [parser-i386-mingw32.def] Error 127
Gem files will remain installed in C:/Program Files/ruby-1.9.3/lib/ruby/gems/1.9.1/gems/json-1.7.3 f
or inspection.
Results logged to C:/Program Files/ruby-1.9.3/lib/ruby/gems/1.9.1/gems/json-1.7.3/ext/json/ext/parser/gem_make.out
An error occured while installing json (1.7.3), and Bundler cannot continue.
Make sure that `gem install json -v '1.7.3'` succeeds before bundling.
If anybody knows how to fix my error so that i can move onto the next one or how i can get a working GemFile.lock, it would be appreciated.

Answer 1

Install json_pure instead on your development machine. This is a version of the json gem that does not require C-extensions (but is a bit slower).
On Heroku you should be able to go with the faster json directly.
If you want to build the C-extension on windows then you might want to look here:
The 'json' native gem requires installed build tools
You can create a windows-specific section in the Gemfile like so:
# Common gems
gem 'xyz'
...
# Platform specific gems
platforms :ruby do
gem 'json'
end
platforms :mswin, :mingw do
gem 'json_pure'
end

Answer 2

Windows isn't properly escaping the space in "C:\Program Files". I haven't used Windows in a while, but a quick search reveals a few fixes.

Answer 3

I had the same problem and found that in my config.yaml file, there was an installation of Ruby 1.9.2 that had a space in it. I had to uninstall that version of Ruby entirely, and remove it from the PATH in environment variables. Then, I re-installed the DevKit and it worked perfectly.