As mentioned above, we're going to install rbenv via the "Basic GitHub Checkout" method. I reproduce them below, but you should consult the latest instructions for Ubuntu on that GitHub page.
Clone down rbenv:
git clone https://github.com/rbenv/rbenv.git ~/.rbenv
Make it more efficient:
cd ~/.rbenv && src/configure && make -C src
Add rbenv to your PATH:
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
And finally run this init script:
Following instructions from the init script run, I added
eval "$(rbenv init -)" to my
~/.bashrc, just below the
export PATH="$HOME/.rbenv/bin:$PATH" line that we added with the echo command above.
Now restart your terminal and/or run
Check your rbenv installation by running
type rbenv. It should say it's a function.
Wanting to build the latest version of Ruby a nice and clean way, I installed ruby-build by running
git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build
Now we can install some versions of Ruby using rbenv.
rbenv install --list gives us all available versions to install.
I'm going with 2.3.3, so I ran
rbenv install 2.3.3. It took a long time to install and then told my the build failed. It suggested running
apt-get install -y libreadline-dev so I did that (prefaced with
sudo) and that software seemed to install successfully.
On second attempt I ran
rbenv install --verbose 2.3.3 so that I could better see what's going on (turns out, it's a lot!). Success this time!
Once that's all installed, I opened a new gnome-terminal window. I was greeted by this shitty message at the top of the terminal window:
The program 'rbenv' is currently not installed. You can install it by typing:
sudo apt install rbenv
but I learned that this can be temporarily solved be running
source ~/.profile. And that it will be solved permanently once you restart Ubuntu/Lubuntu (source: this GitHub issue).
Then I had to set Ruby v. 2.3.3 as my global version of Ruby, which I did with
rbenv global 2.3.3. After that,
ruby --version gave me the familiar:
ruby 2.3.3p222 (2016-11-21 revision 56859) [x86_64-linux]
I definitely want to install the "bundler" gem. To do this, I ran:
gem install bundler, just like with RVM.
From there things seem to be just fine. Installed gems just work so far.