Why does rails server Welcome Aboard site report a different ruby version to rbenv?

Question

I am using rbenv on Debian. Debian came pre-installed with ruby 1.9.3. I installed rbenv and used it to install ruby 2.1.2. I then used rails new to make a fresh rails application.

rbenv versions

gives

system
* 2.1.2 (set by /home/jordanmorris/code/TestRail/.ruby-version)

rbenv global gives 2.1.2
rbenv local (in the new application folder) gives 2.1.2
ruby -v gives 2.1.2
which ruby gives /home/jordanmorris/.rbenv/shims/ruby

However, when I use rails server (node.js), view the 'Welcome aboard site' and click "About your application’s environment", it reports:
Ruby version 1.9.3-p484 (x86_64-linux)

Why is this not displaying the version set with rbenv as expected, and is this a cause for concern?

I only have one version of rails installed, afaik, and it reports correctly (4.1.4).

Answer 1

This answer helped me.

The problem was that I installed rails using sudo.

rbenv operates on a per-user basis. So, rbenv install installed ruby 2.1.2 for jordanmorris, whereas sudo gem install rails installed rails using the only version of ruby/gem installed for root (1.9.3).

Afterwards, every time I ran rbenv or ruby, they used the expected rails version determined by rbenv, but every time I ran rails new or rails server, it would use the rails installed on top of ruby 1.9.3, that being the only instance of rails existing.

I followed these steps to fix it:

1. Uninstall rails and it's dependencies (just because I like to keep a tidy house).
2. Install rails and it's dependencies WITHOUT using sudo.
3. Run rbenv rehash.
4. Regenerate a new application (rails new).

The correct version now displays in the Welcome aboard -> About your application’s environment page.

Also note, the rails new command will create an application which uses spring. Consider installing rbenv-binstubs to avoid stub clashes with rbenv.