Ruby Gems returns "command not found"

Question

Ubuntu 9.10

Just installed newgem

gem install newgem

and when i try

newgem new_project

I get

adam@adam-ubuntu:~$ newgem newproject
newgem: command not found

Ive checked my path via echo $PATH

adam@adam-ubuntu:~$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/home/adam/.gem

and my gem enviroment

adam@adam-ubuntu:~$ gem environment
RubyGems Environment:
  - RUBYGEMS VERSION: 1.3.6
  - RUBY VERSION: 1.8.7 (2009-06-12 patchlevel 174) [x86_64-linux]
  - INSTALLATION DIRECTORY: /usr/lib/ruby/gems/1.8
  - RUBY EXECUTABLE: /usr/bin/ruby1.8
  - EXECUTABLE DIRECTORY: /usr/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-linux
  - GEM PATHS:
     - /usr/lib/ruby/gems/1.8
     - /home/adam/.gem/ruby/1.8
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - http://rubygems.org/

Im not hot with paths etc but all the gem directories listed above are on the path so how come it cant find the command?

Answer 1

Your $PATH variable needs to include the exact path to your Ruby's bin directory. Adding a directory to the PATH does not include it's subfolders. Try adding the bin directory via:

export PATH=$PATH:/home/adam/.gem/ruby/1.8/bin 

or if you installed the gem using sudo:

export PATH=$PATH:/usr/lib/ruby/gems/1.8/bin 

You might want to add this to your .bashrc file, so that you don't have to set this manually every time your open up a new bash.

Answer 2

(Just stealing @John Franklin's comment)

$ gem environment 

Will tell you the EXECUTABLE DIRECTORY. Then put whatever that value is in your PATH like so (in your .bashrc or other shell config file).

export PATH="$PATH:/path/to/bin" 

Reload your shell and you should then be able to use the installed gem.

Answer 3

If you use RVM (most do), then it will take care of this for you. In fact putting it in your path directly may conflict. You have to set a ruby to use though. Run one of these on the command line.

rvm use 1.9.3

or

rvm use --default 1.9.3