How to use gem to install Rails on Ubuntu
After upgrading to Rails 4.2.4 on Ubuntu 14.04 using RVM I needed to do this:
sudo apt-get install libgmp-dev
or
sudo apt-get install libgmp3-dev
Full stacktrace: http://ruby-on-rails-eq8.blogspot.co.uk/2015/10/solving-ubuntu-1404-ruby-c-dependancy.html
How do I use gems with Ubuntu?
Where are my Gems?
You can find where your gems are stored using the gem environment
command. For example:
chris@chris-laptop:~$ gem environment
RubyGems Environment:
- RUBYGEMS VERSION: 1.3.2
- RUBY VERSION: 1.8.7 (2008-08-11 patchlevel 72) [i486-linux]
- INSTALLATION DIRECTORY: /usr/lib/ruby/gems/1.8
- RUBY EXECUTABLE: /usr/bin/ruby1.8
- EXECUTABLE DIRECTORY: /usr/bin
- RUBYGEMS PLATFORMS:
- ruby
- x86-linux
- GEM PATHS:
- /usr/lib/ruby/gems/1.8
- /home/chris/.gem/ruby/1.8
- GEM CONFIGURATION:
- :update_sources => true
- :verbose => true
- :benchmark => false
- :backtrace => false
- :bulk_threshold => 1000
- REMOTE SOURCES:
If you look at the "GEM PATHS:" section you can see that gems can be stored in two places on my laptop: /usr/lib/ruby/gems/1.8
or in the .gem
directory in my home dir.
You can also see that executables are stored in EXECUTABLE DIRECTORY which in this case is /usr/bin
.
Because /usr/bin
is in my path this lets me run cap
, merb
, rails
etc.
Updating your PATH
If for some reason your EXECUTABLE DIRECTORY isn't on your path (for example if it is /var/lib/gems/1.8/bin) then you need to update your PATH variable.
Assuming that you are using the bash shell. You can do this quickly for the current session by typing the following at the shell prompt; let's pretend that you want to add /var/lib/gems/1.8/bin
to the path:
export PATH=$PATH:/var/lib/gems/1.8/bin
and press return. That appends the new directory to the end of the current path. Note the colon between $PATH
and /var/lib/gems/1.8/bin
To set the value for all sessions you will need to edit either your .profile
or .bashrc
file and add the same line to the end of the file. I usually edit my .bashrc
file for no reason other than that's what I've always done. When finished, save the file and then refresh your environment by typing:
bash
at the shell prompt. That will cause the .bashrc
to get reread.
At any point you can check the current value of $PATH
by typing
echo $PATH
at the shell prompt.
Here's a sample from one of my own servers, where my username is "chris" and the machine name is "chris-laptop":
chris@chris-laptop:~$
chris@chris-laptop:~$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
chris@chris-laptop:~$
chris@chris-laptop:~$ export PATH=$PATH:/var/lib/gems/1.8/bin
chris@chris-laptop:~$
chris@chris-laptop:~$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/var/lib/gems/1.8/bin
chris@chris-laptop:~$
My Gem won't load!
"Ruby gems won't load even though installed" highlights a common problem using multiple different versions of Ruby; Sometimes the Gem environment and Gem path get out of sync:
rb(main):003:0> Gem.path
=> ["/opt/ruby1.9/lib/ruby1.9/gems/1.9.1"]
irb(main):004:0> exit
Any Ruby process here is looking only in one place for its Gems.
:~/$ gem env
RubyGems Environment:
- RUBYGEMS VERSION: 1.3.7
- RUBY VERSION: 1.9.1 (2009-05-12 patchlevel 129) [x86_64-linux]
- INSTALLATION DIRECTORY: /opt/ruby1.9/lib/ruby/gems/1.9.1
- RUBY EXECUTABLE: /opt/ruby1.9/bin/ruby1.9
- EXECUTABLE DIRECTORY: /opt/ruby1.9/bin
- RUBYGEMS PLATFORMS:
- ruby
- x86_64-linux
- GEM PATHS:
- /opt/ruby1.9/lib/ruby/gems/1.9.1
- /home/mark/.gem/ruby/1.9.1
- GEM CONFIGURATION:
- :update_sources => true
- :verbose => true
- :benchmark => false
- :backtrace => false
- :bulk_threshold => 1000
- REMOTE SOURCES:
- http://rubygems.org/
Look carefully at the output of gem environment:
- GEM PATHS:
- /opt/ruby1.9/lib/ruby/gems/1.9.1
This isn't the same path as returned by Gem.path:
["/opt/ruby1.9/lib/ruby1.9/gems/1.9.1"]
It's hard to say what exactly caused lib/ruby
to change to lib/ruby1.9
but most likely the developer was working with multiple Ruby versions. A quick mv
or ln
will solve the problem.
If you do need to work with multiple Ruby versions then you really should be using rvm.
Can I install gems with apt-get on Ubuntu?
First, download *.tar file, unpack this file, then go to rubygems directory in your console, and type
ruby setup.rb
That's it :)
Ruby: How to install a specific version of a ruby gem?
Use the -v
flag:
$ gem install fog -v 1.8
Error when run gem install rails
Thanks to all for your help.
At last this problem is solved, when I update my computer using Ubuntu Update Manager.
I don't know why solved the problem after updates. But I am sure it is solved by Updating all.
Specially thanks to majioa.
Problems installing rails in Ubuntu
Here are the steps that I took to install rbenv in ubuntu server
git clone https://github.com/rbenv/rbenv.git ~/.rbenv
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(rbenv init -)"' >> ~/.bashrc
source ~/.bashrc
git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build
rbenv -v
rbenv install 2.5.3
rbenv global 2.5.3
rbenv rehash
ruby -v
gem install bundler
# inside rails application
bundle install
Explanation:
- Line 1: clone rbenv project
- line 2-4: enter rbenv path and settings to your bashrc
- rbenv -v = check whether your rbenv is running correctly
- then install ruby version (I checked above you running version 2.5.3)
- rbenv global 2.5.3 (set version 2.5.3 in any folder paths)
- rbenv rehash (after you set global / local make sure you do rehash)
Can't gem install rails
Turns out I needed to do this:
sudo apt-get install ruby-dev build-essential
Related Topics
How to Display Ruby on Rails Form Validation Error Messages One At a Time
Difference Between Ruby and Ruby on Rails
How to Set Up the Database.Yml File in Rails
Find Key/Value Pairs Deep Inside a Hash Containing an Arbitrary Number of Nested Hashes and Arrays
How to Deal With the Sum of Rounded Percentage Not Being 100
Ruby Regular Expression to Match a Url
How to Clear the Terminal in Ruby
Ruby on Rails - Access Controller Variable from Model
Where Is the Rails Method That Converts Data from 'Datetime_Select' into a Datetime Object
Uploading Multiple Files With Paperclip
Reading the Last N Lines of a File in Ruby
Set Global Default Encoding For Ruby 1.9
Why Does Ruby'S 'Gets' Includes the Closing Newline