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

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

Use the `-v` flag:

$ gem install fog -v 1.8

**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 |

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wheezy/main amd64 Packages
ruby | 4.5 |

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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

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| bash -s stable --ruby # Install only for the user.
#or:# curl -sSL

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| 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.

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

For installing
`gem install gemname -v versionnumber`

For uninstall
`gem uninstall gemname -v versionnumber`

for Ruby 1.9+ use colon.

gem install sinatra:1.4.4 prawn:0.13.0

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]

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).

Prior to installing, you can check the available versions with the list command.

```
gem list ^[gemname]$ --remote --all
gem install [gemname] -v [version]
```