rbenv install --list not showing all versions on ubuntu 18.04 LTS (ruby 2.7.1)

Question

In the attempt to install ruby 2.7.1 using rbenv I noticed the version was not listed on my ubuntu 18.04

$ rbenv install -l | grep 2.7.
  2.7.0-dev
  2.7.0-preview1
  jruby-9.2.7.0
  rbx-2.71828182

Answer 1

So I found this great resource: here

On Linux, you probably installed ruby-build as an rbenv plugin. Updating is easy:

I checked if ruby-build was installed with

$ ruby-build --version
ruby-build 20190615-7-g0e9094b

I checked if ruby-build was associated with rbenv checking the installation path:

$ which ruby-build 
/home/[username]/.rbenv/plugins/ruby-build/bin/ruby-build

git -C ~/.rbenv/plugins/ruby-build pull

as suggested in the resource this solved the problem for me.

---

I also noticed as I tried to install an inexistent version that the command gives the same suggestion

$ rbenv install 2.7.7
ruby-build: definition not found: 2.7.7

See all available versions with `rbenv install --list'.

If the version you need is missing, try upgrading ruby-build:

  git -C /home/[your_user]/.rbenv/plugins/ruby-build pull

Answer 2

As Chilianu Bogdan mentioned, rbenv does not manage version by itself, its done via ruby-build. If you have it as a plugin, git -C "$(rbenv root)"/plugins/ruby-build pull should indeed work.

In case you don't have plugins/ruby-build directory, most probably ruby-build is installed as standalone app, and you need to upgrade it via package manager or source pull & reinstall