Setting up Ruby development setup with rbenv

I wanted to setup ruby source code on my machine. The source on Github has detailed instructions on how to do the setup.

git clone github.com/ruby/ruby
cd ruby
autoconf
./configure
make
make install

worked correctly on Mac OS X and Ruby was installed in usr/local/bin.

I use rbenv for managing Ruby versions. After setting up the Ruby from source, i wanted to use it using rbenv. Why? It will make very easy to switch between dev version and normal version. rbenv shell ruby-dev, do something, make some changes, compile again, test again. rbenv shell 2.1.2, and back to normal.

But as the source Ruby was installed in usr/local/bin, rbenv was not able to find it.

I asked question on #ruby on IRC and Postmodern pointed me to this.

It mentions passing --prefix option to the ./configure command. We can pass the name of directory where we want to install Ruby to this option.

So we can run

./configure --prefix=PATH_TO_INSTALL_RUBY

rbenv by default, installs all rubies in ~/.rbnev/versions

And when we do rbenv versions, it looks for all rubies installed in this directory and lists them.

The content of my ~/.rbnev/versions directory looked like these:

prathamesh ~/.rbenv/versions 2.0.0
$ ls
2.0.0-p247 2.0.0-p353 2.0.0-p481 2.1.0 2.1.1 2.1.2 rbx-2.2.6

prathamesh ~/.rbenv/versions 2.0.0

Now if we give prefix path to configure command, the dev-ruby will be installed in ~/.rbenv/versions

./configure --prefix="$HOME/.rbenv/versions/ruby-dev"

After make and make install, dev ruby was installed in~/.rbnenv/versions in ruby-dev directory.

Now rbenv versions output had ruby-dev also.

prathamesh ~/.rbenv/versions 2.0.0
$ rbenv versions
* system (set by /Users/prathamesh/.rbenv/version)
  2.0.0-p247
  2.0.0-p353
  2.0.0-p481
  2.1.0
  2.1.1
  2.1.2
  rbx-2.2.6
  ruby-dev

prathamesh ~/.rbenv/versions 2.0.0

As ruby-dev is listed by rbenv versions, i can switch to it easily:

rbenv shell ruby-dev

Update

On Mac OS X Sierra, I had to also pass the flag for openssl directory while configuring.

cd ruby
make clean
./configure --prefix="$HOME/.rbenv/versions/ruby-dev" --with-opt-dir="/usr/local/opt/openssl/"
make
make install

This sets up Ruby dev version on my machine and also allows me to switch back and forth using rbenv.