Ruby: How to install a specific version of a ruby gem? - ruby

Question

Using the command-line gem tool, how can I install a specific version of a gem?

Answer 1

Use the -v flag:
$ gem install fog -v 1.8

Answer 2

Use the --version parameter (shortcut -v):
$ gem install rails -v 0.14.1
…
Successfully installed rails-0.14.1
You can also use version comparators like >= or ~>
$ gem install rails -v '~> 0.14.0'
…
Successfully installed rails-0.14.4
With newer versions of rubygems you can tighten up your requirements:
$ gem install rails -v '~> 0.14.0, < 0.14.4'
…
Successfully installed rails-0.14.3
Since some time now you can also specify versions of multiple gems:
$ gem install rails:0.14.4 rubyzip:'< 1'
…
Successfully installed rails-0.14.4
Successfully installed rubyzip-0.9.9
But this doesn't work for more than one comparator per gem (yet).

Answer 3

For installing
gem install gemname -v versionnumber
For uninstall
gem uninstall gemname -v versionnumber

Answer 4

for Ruby 1.9+ use colon.
gem install sinatra:1.4.4 prawn:0.13.0

Answer 5

As others have noted, in general use the -v flag for the gem install command.
If you're developing a gem locally, after cutting a gem from your gemspec:
$ gem install gemname-version.gem
Assuming version 0.8, it would look like this:
$ gem install gemname-0.8.gem

Answer 6

You can use the -v or --version flag. For example
gem install bitclock -v '< 0.0.2'
To specify upper AND lower version boundaries you can specify the --version flag twice
gem install bitclock -v '>= 0.0.1' -v '< 0.0.2'
or use the syntax (for example)
gem install bitclock -v '>= 0.0.1, < 0.0.2'
The other way to do it is
gem install bitclock:'>= 0.0.1'
but with the last option it is not possible to specify upper and lower bounderies simultaneously.
[gem 3.0.3 and ruby 2.6.6]

Answer 7

Linux
To install different version of ruby, check the latest version of package using apt as below:
$ apt-cache madison ruby
ruby | 1:1.9.3 | http://ftp.uk.debian.org/debian/ wheezy/main amd64 Packages
ruby | 4.5 | http://ftp.uk.debian.org/debian/ squeeze/main amd64 Packages
Then install it:
$ sudo apt-get install ruby=1:1.9.3
To check what's the current version, run:
$ gem --version # Check for the current user.
$ sudo gem --version # Check globally.
If the version is still old, you may try to switch the version to new by using ruby version manager (rvm) by:
rvm 1.9.3
Note: You may prefix it by sudo if rvm was installed globally. Or run /usr/local/rvm/scripts/rvm if your command rvm is not in your global PATH. If rvm installation process failed, see the troubleshooting section.
Troubleshooting:
If you still have the old version, you may try to install rvm (ruby version manager) via:
sudo apt-get install curl # Install curl first
curl -sSL https://get.rvm.io | bash -s stable --ruby # Install only for the user.
#or:# curl -sSL https://get.rvm.io | sudo bash -s stable --ruby # Install globally.
then if installed locally (only for current user), load rvm via:
source /usr/local/rvm/scripts/rvm; rvm 1.9.3
if globally (for all users), then:
sudo bash -c "source /usr/local/rvm/scripts/rvm; rvm 1.9.3"
if you still having problem with the new ruby version, try to install it by rvm via:
source /usr/local/rvm/scripts/rvm && rvm install ruby-1.9.3 # Locally.
sudo bash -c "source /usr/local/rvm/scripts/rvm && rvm install ruby-1.9.3" # Globally.
if you'd like to install some gems globally and you have rvm already installed, you may try:
rvmsudo gem install [gemname]
instead of:
gem install [gemname] # or:
sudo gem install [gemname]
Note: It's prefered to NOT use sudo to work with RVM gems. When you do
sudo you are running commands as root, another user in another shell
and hence all of the setup that RVM has done for you is ignored while
the command runs under sudo (such things as GEM_HOME, etc...). So to
reiterate, as soon as you 'sudo' you are running as the root system
user which will clear out your environment as well as any files it
creates are not able to be modified by your user and will result in
strange things happening.

Answer 8

Prior to installing, you can check the available versions with the list command.
gem list ^[gemname]$ --remote --all
gem install [gemname] -v [version]