Why can't Ruby find Rake?

Question

I was using the Rails 3 beta gem yesterday but went back to 2.3.8, and, after cleaning the system gems, I was trying to run a simple Rake task and got this:

Peleliu:haml jayfallon$ sudo rake install
/Library/Ruby/Site/1.8/rubygems.rb:779:in `report_activate_error': Could not find RubyGem rake (>= 0) (Gem::LoadError)
 from /Library/Ruby/Site/1.8/rubygems.rb:214:in `activate'
 from /Library/Ruby/Site/1.8/rubygems.rb:1082:in `gem'
 from /usr/bin/rake:18

I am not sure if it has to do with my path being borked or not.

RubyGems Environment:
  - RUBYGEMS VERSION: 1.3.7

  - RUBY VERSION: 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin10.0.0]
  - INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/1.8
  - RUBY EXECUTABLE: /usr/local/bin/ruby
  - EXECUTABLE DIRECTORY: /usr/local/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86-darwin-10
  - GEM PATHS:
     - /usr/local/lib/ruby/gems/1.8
     - /Users/jayfallon/.gem/ruby/1.8
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
     - :sources => ["http://gems.rubyforge.org/", "http://gems.github.com", "http://gems.github.com", "http://gems.github.com", "http://gems.github.com", "http://gems.github.com", "http://gems.github.com", "http://gems.github.com", "http://gems.github.com", "http://gems.github.com", "http://gemcutter.org/"]
  - REMOTE SOURCES:

     - http://gemcutter.org/

Ryan Ryan · Accepted Answer · 2012-10-13T19:03:25

It looks like rake is trying to run from /usr/bin/rake, the system version of Ruby, while you have a custom install of Ruby in /usr/local.

Make sure you have the rake gem installed for the Ruby installation you're using
Make sure the rake command is in a directory on your $PATH.

which gem should return the rubygems install from /usr/local/bin. If not, that's the first problem to solve. Then you want to make sure you have the rake gem in your /usr/local Ruby installation:

gem list | grep rake

should tell you if the gem is installed. If not, run gem install rake.

At this point, which rake should point to something in your /usr/local path. If it doesn't use find /usr/local | grep rake to figure out where your Ruby install is keeping gem executables and add that directory to your loadpath.

As a side note, if you're using your own install of Ruby, you might find rvm or rbenv helpful for managing installs and gems.

Why can't Ruby find Rake?

3 Answers