rake doesn't work in Rails4

Question

I tried to rake in Ruby on Rails4, but it didn't work. When i used Ruby which is installed at first in my mac, there was no error. But after i installed rbenv, this error occurs. How can I fix this problem??

$ bundle exec rake assets:precompile
/Library/Ruby/Gems/2.0.0/gems/bundler-1.5.3/lib/bundler/runtime.rb:220: warning: Insecure world writable dir /usr/local in PATH, mode 040777
/Library/Ruby/Gems/2.0.0/gems/bundler-1.5.3/lib/bundler/spec_set.rb:92:in `block in materialize': Could not find rake-10.3.1 in any of the sources (Bundler::GemNotFound)
from /Library/Ruby/Gems/2.0.0/gems/bundler-1.5.3/lib/bundler/spec_set.rb:85:in `map!'
from /Library/Ruby/Gems/2.0.0/gems/bundler-1.5.3/lib/bundler/spec_set.rb:85:in `materialize'
from /Library/Ruby/Gems/2.0.0/gems/bundler-1.5.3/lib/bundler/definition.rb:133:in `specs'
from /Library/Ruby/Gems/2.0.0/gems/bundler-1.5.3/lib/bundler/definition.rb:178:in `specs_for'
from /Library/Ruby/Gems/2.0.0/gems/bundler-1.5.3/lib/bundler/definition.rb:167:in `requested_specs'
from /Library/Ruby/Gems/2.0.0/gems/bundler-1.5.3/lib/bundler/environment.rb:18:in `requested_specs'
from /Library/Ruby/Gems/2.0.0/gems/bundler-1.5.3/lib/bundler/runtime.rb:13:in `setup'
from /Library/Ruby/Gems/2.0.0/gems/bundler-1.5.3/lib/bundler.rb:119:in `setup'
from /Library/Ruby/Gems/2.0.0/gems/bundler-1.5.3/lib/bundler/setup.rb:17:in `<top (required)>'
from /Users/Fumiya/.rbenv/versions/2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/Fumiya/.rbenv/versions/2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'

Answer 1

specify in your gemfile

gem 'rake', '10.3.1'

then

bundle install

and do

bundle exec rake assets:precompile