Question

Apologies for the topic title, couldn’t resist.

Basically, For no reason whatsoever apart from trying out different things. I want to implode RVM and try out rbenv. Nothing against RVM, just want to try different peoples software and try different things out.

I can get rid of RVM and install rbenv no problem. Could you guys confirm a few things for me.

Firstly, if I do the above, and then install a few different ruby versions. I know I can place a .ruby-version file in a projects root directory to specify a specific ruby version but then when I say gem install <gemname> I take it that is installed globally for that ruby version.

If I then use bundler per project to manage what gems are used and I specify a gem version, what happens if the version specified in the lock file is different to the currently installed version and what happens if it’s vice versa?

I just need a bit of clarification on what’s doing what in regards to ruby, versions, gems and their versions.

Answer 1

One of the (many) lovely things about rbenv is that you can so easily look right at your ruby installation to see what’s going on. For example, on my machine I can open ~/.rbenv and there’s versions containing my ruby installations, such as 1.9.3-p327. Opening that, I can keep drilling down to see my gems installed for that version of ruby (in ~/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems). It is then trivial to run gem list or gem install somegem and confirm that what’s being affected is this very collection of gems – if this is the current ruby (set in rbenv global and starred in rbenv versions).

In short, everything about your system thinks that ruby means this version of ruby and that its library is this library.

For Bundler, you’ll need to install rbenv-bundler. A nice tutorial (easily found with Google) is here: http://dan.carley.co/blog/2012/02/07/rbenv-and-bundler/