Trying to install dev kit for ruby in windows 7 but fails

Question

I am trying to install the dev kit for ruby for the CommandT plugin for vim and I am hit with

C:\Users\Administrator>gem install rdiscount --platform=ruby
ERROR:  Error installing rdiscount:
        The 'rdiscount' native gem requires installed build tools.

Please update your PATH to include build tools or download the DevKit
from 'http://rubyinstaller.org/downloads' and follow the instructions
at 'http://github.com/oneclick/rubyinstaller/wiki/Development-Kit'

I have already run install devkit at shown below

C:\devkit>ruby dk.rb init
[INFO] found RubyInstaller v1.9.3 at C:/Ruby193

Initialization complete! Please review and modify the auto-generated
'config.yml' file to ensure it contains the root directories to all
of the installed Rubies you want enhanced by the DevKit.

C:\devkit>ruby dk.rb review
Based upon the settings in the 'config.yml' file generated
from running 'ruby dk.rb init' and any of your customizations,
DevKit functionality will be injected into the following Rubies
when you run 'ruby dk.rb install'.

C:/Ruby193

C:\devkit>ruby dk.rb install
[INFO] RubyGems override already in place for C:/Ruby193, skipping.
[WARN] DevKit helper library already exists for C:/Ruby193, skipping.

What could be possibly going wrong?

Edit: I tried

c:\devkit>ruby dk.rb install --force

Configures an MSYS/MinGW based Development Kit (DevKit) for
each of the Ruby installations on your Windows system. The
DevKit enables you to build many of the available native
C-based RubyGems that don't yet have a binary gem.

Usage: ruby dk.rb COMMAND

where COMMAND is one of:

  init     prepare DevKit for installation
  review   review DevKit install plan
  install  install required DevKit executables

uninstalled and installed again with a clean directory. But the error remains the same.

Solution 1

On this lines:

C:\devkit>ruby dk.rb install
[INFO] RubyGems override already in place for C:/Ruby193, skipping.
[WARN] DevKit helper library already exists for C:/Ruby193, skipping.

It's telling you that it didn't install the DevKit for Ruby because it already had a previous DevKit registered there.

It might be possible you relocated a previous installation of DevKit, in which case you need to perform ruby dk.rb install --force to override the RubyGems and DevKit helper script it previously skipped.

Hope that helps.

Solution 2

I had the same problem with ruby dk.rb install, however, as suggested with the --force option it has successfully installed my devkit which in turn had resolved a gem install failure I was getting with JSON 1.4.6 gem.