Documenting the process of moving from RVM to rbenv. Also get some of the
cool tools
working. This does not include anything about rails. And none of this
should require sudo. You’ll probably want to consult the individual project
pages at some point to learn more, but this guide should contain every setup
instruction needed for all the tools to work.
(Note that this is a dump of the steps I performed in week #1 and is not yet fully cleaned up/ordered/tested. I’ve worked through these steps on Arch and Ubuntu linux.)
This little tutorial enables you to install (ruby-build) and use (rbenv) multiple versions of ruby, isolate project gems (gemsets and/or bundler), and automatically use appropriate combinations of rubies and gems.
The two things to accomplish:
- Having at least one reliable locally installed Ruby
- Project-specific Gemsets
(Note that I’m using using Zsh in the examples.)
I’ve loved using RVM. It did do a surreptitious thing with my environment (a
shell file clobber setting) that I still don’t have a handle on (beyond
overriding things with shell functions). And it’s a little too sophisticated
to keep in my head everything it’s doing. If rbenv can eliminate any of the
magic of environment management, then I’ll give it a go.
(ignore this, NYI) As this is a multi-repo configuration, you might want to consider using git magnet.
Git it.
% git clone git://github.com/sstephenson/rbenv.git ~/.rbenv
Enable it.
% echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.zshrc
% echo 'eval "$(rbenv init -)"' >> ~/.zshrc # or equivalent
% exec $SHELL
You haven’t done anything interesting yet. Hang tight.
For more rationale details, consult the rbenv
project page.
(skip this) See how it works:
##% which ruby
##/home/mde/.rbenv/shims/ruby
##% <`!!`
##«see that it just runs: rbenv exec ruby …»
Your system should have gcc et al installed already. In Ubuntu this is
build-essential and in Arch you’ve already got them, of course.
% mkdir -p ~/.rbenv/plugins
% cd ~/.rbenv/plugins
% git clone git://github.com/sstephenson/ruby-build.git
Now we’re done manually installing things to specific places.
% cd ~/anywhere
For Ubuntu users, make sure you’ve installed the zlib1g-dev apt package
before building any rubies (to avoid this
issue).
Find out which rubies are available. Wow, you can even tab-complete these:
% rbenv install 1.8.7-p«tab»
1.8.7-p249 1.8.7-p302 1.8.7-p334 1.8.7-p352 1.8.7-p357 1.8.7-p358
Get a few (be patient):
% rbenv install 1.9.3-p125
% rbenv install jruby-1.6.7
% rbenv install rbx-2.0.0 # rubinius; why not
You need to “rehash” to regenerate rbenv’s “shims” after installing a new ruby.
% rbenv rehash
Now do it again for practice:
% rbenv rehash
You’re going to do that almost every time you install a gem to generate
the shims. Get used to it or make rbenv install an alias to also rehash.
You’ve probably already got a system ruby installed. See them all now.
(Actually, I believe system ruby is not listed here.)
% rbenv versions
1.8.7-p358
1.9.3-p125 (set by /home/mde/.rbenv/version)
jruby-1.6.7
rbx-2.0.0-dev
Turn one on for persistent “global” use across your system (for your user
anyway). Note to RVM users: forget the verb use. global, local,
and shell are your new enablers.
% rbenv global jruby-1.6.7
% ruby -ve 'puts "it works"'
jruby 1.6.7 (ruby-1.8.7-p357) (2012-02-22 3e82bc8) (Java HotSpot(TM)…
it works
Quickly switch back and forth in a session with: rbenv shell 1.«tab»
You should know that these are all being installed to your ~/.rbenv/versions
dir.
(If you intend to install ruby 1.8.7, you might need this workaround.)
You can skip this section if you want to just always install gems directly into your projects.
Use the rbenv “plugin” subtool rbenv-gemset.
% cd ~/.rbenv/plugins
% git clone git://github.com/jamis/rbenv-gemset.git
You should now have a new gemset command in rbenv:
% rbenv gemset «tab»
active create delete file list version
% rbenv gemset create 1.9.3-p125 helloset
(Note that tab-completion is not yet working for the gemset command.)
That set up a directory for you in
~/.rbenv/versions/1.9.3-p125/gemsets/helloset. But now it’s up to you to do the
other half manually: setting the name of your gemset. You need to create a
tiny file, in this case containing helloset.
% >.rbenv-gemsets
helloset
Now when you gem install (see “Bundler” section below) something it will go
to your helloset gem area.
You can combine use of multiple gemsets with it.
The big benefit to this setup is enabling each project to use a different set of differently versioned gems.
% cd $TMPDIR/hello
% >.rbenv-gemsets
helloset
Bundler is the tool for managing your project dependencies. In fact, we’ll (almost) never even install a gem directly, without Bundler.
NOTE: Although the tool is called “Bundler,” its command is actually bundle.
This has caused some confusion. You’ll actually be fine whether you install
the bundle or bundler gem, but the command will alwyas be bundle.
Now that you’re working with multiple rubies, every ruby will need its own bundler.
Now, what gem do we actually have?
% whence -av gem
gem is /home/mde/.rbenv/shims/gem
gem is /usr/bin/gem
That didn’t make it too clear. Every ruby actually provides its own gem
command (er, maybe not 1.8?). Here’s how to see it:
% rbenv which gem
/home/mde/.rbenv/versions/1.9.3-p125/bin/gem
And what Bundler?
% rbenv which bundle
rbenv: bundle: command not found
Hmm. Now we can see that we need to install it manually. So this is
bootstrapping; it’ll be the only time we need to use gem directly for
installing. (bundler is also a good global gemset install; see below.)
% gem install bundler
…
% rbenv which bundle
/home/mde/.rbenv/versions/1.9.3-p125/bin/bundle
Great. That was quick and easy.
% which -a bundle
bundle is /home/mde/.rbenv/shims/bundle
bundle is /usr/bin/bundle
Now do it for all your rubies (and every time you install another ruby).
Like RVM, rbenv can do global gemsets, too (though I haven’t tried it yet).
% >Gemfile
source "http://rubygems.org"
gem "sinatra", "1.3.2"
gem "compass", "0.12.1"
% bundle install
% cd ~/proj/foo
% rbenv shell 1.9.3-p125
% rbenv local «tab»
1.8.7-p358 1.9.3-p125 jruby-1.6.7 rbx-2.0.0-dev system --unset
% rbenv local jruby-1.6.7
Set a local persistent version.
% rbenv local rbx-2.0.0-dev
% cat .rbenv-version
rbx-2.0.0-dev
rbenv is a handful to be typing often. I presently use:
% alias rb=rbenv
though r and b are terribly distant to type on QWERTY.
Eventually new rubies will release and you’ll want to keep up. This means moving your installed gems along with them.
FIXME: I HAVEN'T DONE THIS YET