How to have multiple versions of Ruby AND Rails, and their combinations on Windows?

Question

Since Windows doesn't support rvm (Ruby version Manager), how do we have

• Ruby 1.8.7, Rails 2.3.8
• Ruby 1.8.7, Rails 3.0.0
• Ruby 1.9.2, Rails 3.0.0

on the same PC? Virtual machines can be used but it is kind of troublesome.

Answer 1

Use uru. It is a multi-platform ruby environment manager. You can download the Windows version here: https://bitbucket.org/jonforums/uru/wiki/Downloads

Install the tool

Assuming C:\tools is on PATH and uru_rt.exe was extracted to C:\tools

C:\tools>uru_rt admin install

This adds uru.bat file to the tools directory.

Register ruby

uru admin add C:\ruby200\bin

List available rubies

uru ls
174         : jruby 1.7.4 (1.9.3p392) 2013-05-16 2390d3b on Java HotSpot(TM)
200p255     : ruby 2.0.0p255 (2013-07-07 revision 41812) [i686-linux]
=> system   : ruby 2.1.0dev (2013-07-06 trunk 41808) [i686-linux]

Switch ruby version

uru 174
---> Now using jruby 1.7.4 tagged as `174`

More commands can be found here: https://bitbucket.org/jonforums/uru/wiki/Examples

---

Old answer

I use Pik to manage multiple versions of ruby on a Windows machine.

Install the pik gem

> gem install pik
Successfully installed pik-0.2.6
1 gem installed

Install pik to a location that’s in your path, but someplace other than your ruby\bin dir.

>echo %path%
PATH=c:\pik;c:\ruby\Ruby187\bin;

>pik_install C:\pik
Thank you for using pik.

Installing to C:\pik
pik is installed

Install Ruby 1.9.2 using RubyInstaller and add the new Ruby version to pik registry.

>pik add C:\Ruby192\bin

List the available Ruby versions:

>pik list
187: ruby 1.8.7 (2010-01-10 patchlevel 249) [i386-mingw32] *
192: ruby 1.9.2p0 (2010-08-18) [i386-mingw32]

To switch to Ruby 1.9.2:

>pik 192
>pik list
187: ruby 1.8.7 (2010-01-10 patchlevel 249) [i386-mingw32]
192: ruby 1.9.2p0 (2010-08-18) [i386-mingw32] *

To switch between different versions of Rails:

In Rails 2.x, set the RAILS_GEM_VERSION in config/environment.rb file:

RAILS_GEM_VERSION = '= 2.3.8' unless defined? RAILS_GEM_VERSION

In rails 3, use the Gemfile to specify the Rails version:

gem "rails", "3.0.0"

Answer 2

After installing and registering all your ruby installations with uru, you'll need to install DevKit for each of the ruby versions installed. For installation follow these instructions.

I generally store the DevKit next to the version of Ruby to which it belongs, for example, C:\Ruby\Ruby193\DevKit where Ruby193 is the folder containing the 193 version of Ruby that I registered with uru.

Answer 3

From what I could tell, uru only manages versions of RUBY.

For versions of RAILS, where you've already 2 or more versions on your local maching, to open a project in one's development environment, using an older version of rails, you enter the following in the command window:

rails _3.2.11_ s

where 3.2.11 represents the version of RAILS you want it to use, which you want to be the same version as listed in your project's file:

Gemfile.lock

Answer 4

I wrote myself a little batch file which creates a junction (aka symlinks) on the NTFS. The idea is to keep the PATH untouched. The path always contains c:\devkit\bin;c:\ruby\bin;.... The following Batch file changes the links to the actual directories.

@echo off
echo 1 - Ruby 1.9.3
echo 2 - Ruby 2.0.0 (32 bit)
echo 3 - Ruby 2.0.0 (64 bit)
choice /C 123 /M "Which Ruby? "

if errorlevel 255 goto confused
if errorlevel 3 goto 3
if errorlevel 2 goto 2
if errorlevel 1 goto 1
if errorlevel 0 goto 0
goto confused

:1
if exist c:\ruby rmdir c:\ruby
if exist c:\devkit rmdir c:\devkit
mklink /j c:\ruby c:\ruby193
mklink /j c:\devkit c:\devkit-4.5.2
goto end

:2
if exist c:\ruby rmdir c:\ruby
if exist c:\devkit rmdir c:\devkit
mklink /j c:\ruby c:\ruby2-x86
mklink /j c:\devkit c:\devkit-x64
goto end

:3
if exist c:\ruby rmdir c:\ruby
if exist c:\devkit rmdir c:\devkit
mklink /j c:\ruby c:\ruby2-x64
mklink /j c:\devkit c:\devkit-x64
goto end

:confused
echo I'm confused ...

:end
ruby -v