gem install json -v 1.7.3 gives 'Please update

问题:

When I run:

rails new blog

I get:

Installing json (1.7.3)
Gem::InstallError: The 'json' 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'
An error occurred while installing json (1.7.3), and Bundler cannot continue.
Make sure that `gem install json -v '1.7.3'` succeeds before bundling.

When I run:

gem install json -v 1.7.3

I get:

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'm using Windows 8. I do have c:\ruby193\bin in my path. What do I do to remedy these errors?

回答1:

Make sure you install the devkit (ticking the checkboxes that will update the path) : You might need to reinstall ruby too.

Install the DevKit

Download Development Kit from here http://rubyinstaller.org/downloads/

DevKit url at this time For use with Ruby 1.8.7 and 1.9.3: DevKit-tdm-32-4.5.2

For use with Ruby 2.0 and above (32bits version only): DevKit-mingw64-32-4.7.2

For use with Ruby 2.0 and above (x64 - 64bits only) DevKit-mingw64-64-4.7.2

Follow instructions here.

Or short instructions :

Unzip the zip

open command-line and go to unzipped folder

ruby dk.rb init

ruby dk.rb install

gem install rdiscount --platform=ruby

回答2:

sometimes when you run the ruby dk.rb init you got an error like this

for fixing this problem you have to change the encoding of the command prompt windows . to do this type chcp 1256 and you will receive this message : Active code page: 1256

now you can run that command without problem .

good luck .

回答3:

If you know that you have the proper DevKit installed (eg: via chocolatey), then you simply need to run the included script to set up environment variables.

In cmd:

C:\> d:\path\to\DevKit2\devkitvars.bat

In PowerShell:

PS> . d:\path\to\DevKit2\devkitvars.ps1

These scripts will set up the correct paths in your current command window.

回答4:

Delete the old DevKit folder before you extract the new one which you will download from one of the following links, based on your configuration:

DevKit url at this time For use with Ruby 1.8.7 and 1.9.3: https://github.com/downloads/oneclick/rubyinstaller/DevKit-tdm-32-4.5.2-20111229-1559-sfx.exe

For use with Ruby 2.0 and above (32bits version only): http://dl.bintray.com/oneclick/rubyinstaller/DevKit-mingw64-32-4.7.2-20130224-1151-sfx.exe2

For use with Ruby 2.0 and above (x64 - 64bits only) http://dl.bintray.com/oneclick/rubyinstaller/DevKit-mingw64-64-4.7.2-20130224-1432-sfx.exe3