How to change ruby version

Question

Ruby 1.8 and 1.9 are installed in my Ubuntu machine. I've just installed Ruby 2.0.0 from ppa:brightbox/ruby-ng-experimental to install a bundle which requires 2.0.0. Now all 1.8, 1.9 and 2.0 are installed though I can't tell bundle to use 2.0:

$ bundle install
$ Your Ruby version is 1.9.3, but your Gemfile specified 2.0.0

RVM fails to change version:

$ rvm 2.0
$ ruby-2.0.0-p451 is not installed.
$ To install do: 'rvm install ruby-2.0.0-p451'

RBENV also does not recognize 2.0:

$ rbenv global 2.0.0-p451
$ rbenv: version `2.0.0-p451' not installed

what ruby version manager you use? you try `rvm --default use 2.0.0` or `rvm use 2.0.0`? — Roman Kiselenko, Feb 26 '14 at 07:30
have you tried `rvm install ruby-2.0.0`? also provide `rvm list` — Малъ Скрылевъ, Feb 26 '14 at 07:50
@МалъСкрылевъ That't not an option. I already installed Ruby 2.0 from PPA and I want to use that one. — sorush-r, Feb 26 '14 at 07:52
Do you have both rbenv and RVM installed? If so, don't do that, pick one or the other. Using both will make you crazy. If you installed Ruby v2.0 outside of rbenv or RVM, you'll have to manually manage it because neither sandbox tool will know about v2.0, nor can they help you switch to it. You should either work within one of them, or delete them all and do it all manually because you're going to get your system quite confused in no time. — the Tin Man, Feb 26 '14 at 07:56
@sorush-r use `rvm mount` to pick up the already installed ruby — Малъ Скрылевъ, Feb 26 '14 at 08:57
@МалъСкрылевъ `ERROR: Unrecognized command line argument: 'mount' ( see: 'rvm usage' ) ` — sorush-r, Feb 26 '14 at 11:18
what says `rvm help mount`? If the similar error, reinstall rvm — Малъ Скрылевъ, Feb 26 '14 at 11:26
It says: `cat: /usr/share/ruby-rvm/README: No such file or directory` — sorush-r, Feb 26 '14 at 11:51
I think it's already installed. `rvm -v` says `rvm 1.6.9 by Wayne E. Seguin (wayneeseguin@gmail.com) [https://rvm.beginrescueend.com/]` ` — sorush-r, Feb 26 '14 at 13:08
You can list all available versions with `rbenv install --list` if you use rbenv. — onurozgurozkan, Feb 27 '14 at 00:56
HI try these links [http://wiki.brightbox.co.uk/docs:ruby-ng ] [http://stackoverflow.com/questions/18490591/how-to-install-ruby-2-on-ubuntu-without-rvm ] [http://brightbox.com/docs/ruby/ubuntu/ ] — Kanna, May 13 '14 at 10:23

Felix · Accepted Answer · 2018-09-19T06:40:07.643

There is lots of advise in the comments to your question, some of it is advanced-ish rbenv or rvm usage.

My advice: Decide on how to manage multiple rubies - either use your OS package manager (in your case the apt-get/PPA stuff) OR rvm OR rbenv.

For the OS package manager, there should be a way to call ruby with version explicitely (e.g. /usr/bin/ruby1.9.3), or research on and call update-alternative. As bundler comes with a gem, you might get the interpreters confused here.

For rvm, change ruby version with rvm use 2.5.1 (once it is installed).

For rbenv I actually do not know but it should be trivial, too (and people are happy with it; it just happens that I tried rvm first and it worked like a charm, never evaluated rbenv).

I usually install one "system" ruby (apt-get install ruby1.9.3) and use rvm afterwards. You can still switch to the packaged "production" ruby with rvm use system.

Update 2017: Most distros ship with a ruby version installed already, so you probably don't have to install it manually. Run ruby -v or which ruby to see if a ruby interpreter is already installed.

In your case I would probably deinstall all system rubys (apt-get purge ...), remove the PPAs, remove your ~/.rvm and rbenv and start from scratch (install packaged stable ruby, then rvm and use rvm (r.g. rvm install 2.3.1) from there on).

Gamaliel · Answer 2 · 2017-03-17T20:02:51.040

5

Adding the repository If you’re using Ubuntu 14.04 (Trusty) or newer then you can add the package repository like this:

$ sudo apt-get install software-properties-common
$ sudo apt-add-repository ppa:brightbox/ruby-ng
$ sudo apt-get update

Install ruby switch

$ sudo apt-get install ruby-switch

Commands of utiliy

ruby -v
ruby-switch --list

Example

$ sudo ruby-switch --set ruby2.1

Hope this help you.

From: https://www.brightbox.com/docs/ruby/ubuntu/

edited Mar 17 '17 at 20:02

answered Mar 17 '17 at 19:46

Gamaliel

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Trying to install ruby-switch gave me this: Package ruby-switch is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'ruby-switch' has no installation candidate – lubrum Jan 03 '21 at 19:52
1

Maybe is outdated, I mean, check if the repository is available in your Ubuntu version. As I know at this date Brightbox doesn't have Ruby release to Ubuntu 20. That's my last try and need to install it another way. – Gamaliel Jan 05 '21 at 02:12

score 1 · Answer 3 · answered Dec 04 '22 at 18:58

1

export PATH=$PATH:~yourusername/.rbenv/shims/ruby

This will set ruby in your shell to the current rbenv ruby.

You can put this line in your .bashrc or other init file.

answered Dec 04 '22 at 18:58

dezman

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score 0 · Answer 4 · edited Apr 20 '23 at 16:00

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$/bin/bash --login`

Then add the Ruby version you have (for example 2.5, 2.7)

$rvm use 2.5

edited Apr 20 '23 at 16:00

ruud

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answered Apr 18 '23 at 07:55

Srinivash

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score 0 · Answer 5 · answered Jul 15 '23 at 20:22

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I tried all solutions listed above, but after I open a new terminal, the version always goes back to the old one. For me, the way I solved the problem is by running this rvm --default use **RUBY_VERSION_YOU_NEED**

answered Jul 15 '23 at 20:22

feigo808

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How to change ruby version

5 Answers5