RVM Autolibs: Automatic Dependency Handling and Ruby 2.0

Last month marked a very important milestone for Rubyists - The release of Ruby 2.0.0. It comes with new RubyGems and new dependencies, including OpenSSL. RVM was not doing much to resolve dependencies earlier, instead installing LibYAML because it is required for RubyGems to function properly. The situation changes with OpenSSL as it’s now a bigger dependency. Initially for Ruby 2.0.0-rc1 RVM was installing OpenSSL. However compiling OpenSSL is not that easy task as with LibYAML, it also duplicates the effort with distribution maintainers to compile a working OpenSSL.

A new approach

To make this work, RVM takes a new approach. It will now work with the system package manager to install required libraries. This is no easy feat, as different systems have different names for packages, with some of them being available by default and some not available at all.

It’s easy when it’s easy

It’s easy to use an existing package manager on any of the systems. The trouble begins when distribution does not have a default package manager which is the case for OSX. There are a number of package managers, and none of them are popular enough to be de-facto standard. With this in mind it’s necessary for RVM to find an existing package manager and install one when there isn’t one available.

Sensible defaults

When autolibs was first added RVM assumed users wanted to have all the work done for them. Unfortunately we fast hit the reality that some users know better and still prefer to install dependencies manually. There had to be a compromise to fit both needs. In the end RVM will by default detect available libraries and fail if they are not available. Users have now option to switch to other modes including “do it all for me” and “let me do it myself”.

Do it all for me

Users who want get the libraries installed automatically can use autolibs mode 4 aka. enable. This will tell RVM to find package manager (installing one if necessary), install all dependencies, and finally use them for compiling rubies. If the package manager is not available (on OS X) Homebrew will be installed. However users can select what package manager will be installed with autolibs modes osx_port, osx_fink and smf. The smf package manager is for the lesser known RailsInstaller’s SM Framework.

For systems with a default package manager mode 4 is the same as mode 3, which means install missing packages.

Let me do it myself

For users that do not want RVM do the automatic there are two modes that will come in handy. Mode 1 allows users to instruct RVM to pick the libraries and just show warnings if they are missing. In case when even the automatic detection is to much it can be turned off with mode 0. Unfortunately there is a caveat. Given that the code is more dynamic, there is no longer a list to show what is required. This means that some libraries are picked depending on current system state. So if users do not want to use the automated modes (3 or 4) then RVM can only report what is missing, not all the dependencies that might be required on similar distributions.

Some tricks

To install RVM with Ruby, Ruby on Rails and all the required libraries (aka. the poor man’s RailsInstaller):

\curl -L https://get.rvm.io | bash -s stable --rails --autolibs=enable

To use rvm in deployment where sudo requires extra handling like in capistrano:

task :install_requirements do
sudo “rvm --autolibs=4 requirements #{rvm_ruby_string}”
task :install_ruby do
run “rvm --autolibs=1 install #{rvm_ruby_string}”

You can find more details about autolibs in our docs https://rvm.io/rvm/autolibs.

Let us know

We have been testing autolibs code for some time now, but as always bringing it to wider audience creates new cases, detects new flaws, or just creates possible misunderstandings. We are open to get those fixed please report issues to RVM’s issue tracker https://github.com/wayneeseguin/rvm/issues or talk to use using IRC http://webchat.freenode.net/?channels=rvm

Thanks for using RVM, and may the autolibs feature improve your Ruby experience.

Other Announcements

Officially opening RVM 2.0 work.

RVM 1.19 was last release where we included new features (Autolibs), all new feature requests will be deferred to RVM 2.0. We still will provide support, work on fixing bugs and update all software versions as long as RVM 2.0 is not released and marked stable. But to allow the work on RVM 2.0 we need to freeze the feature set available in RVM 1.x.

Updates to the website!

RVM has long had an unorganized website that simply adds information and has become hard for both maintainers and for users and since we are opening up development on RVM 2.0 work we are also opening up development on a brand new site! We hope to clean up and simplify the way you interact with the site, implement a cleaner design using Twitter’s Bootstrap and make the documentation more like man pages so that they can be ported back and forth between RVM and the website making everything more seamless not only for us, but for users also.


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