rvm and GEM_HOME

bundle_install_in_project

$ bundle install
Fetching source index for http://rubygems.org/
Installing rake (0.9.2) 
Installing abstract (1.0.0) 
Installing activesupport (3.0.5) 
Installing builder (2.1.2) 
Installing i18n (0.6.0) 
Installing activemodel (3.0.5) 
Installing erubis (2.6.6) 
Installing rack (1.2.3) 
Installing rack-mount (0.6.14) 
Installing rack-test (0.5.7) 
Installing tzinfo (0.3.28) 
Installing actionpack (3.0.5) 
Installing mime-types (1.16) 
Installing polyglot (0.3.1) 
Installing treetop (1.4.9) 
Installing mail (2.2.19) 
Installing actionmailer (3.0.5) 
Installing arel (2.0.10) 
Installing activerecord (3.0.5) 
Installing activeresource (3.0.5) 
Using bundler (1.0.15) 
Installing thor (0.14.6) 
Installing railties (3.0.5) 
Installing rails (3.0.5) 
Installing sqlite3 (1.3.3) with native extensions 
Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.


$ ls $GEM_HOME/gems

abstract-1.0.0
actionmailer-3.0.5
actionpack-3.0.5
activemodel-3.0.5
activerecord-3.0.5
activeresource-3.0.5
activesupport-3.0.5
arel-2.0.10
builder-2.1.2
bundler-1.0.15
erubis-2.6.6
i18n-0.6.0
mail-2.2.19
mime-types-1.16
polyglot-0.3.1
rack-1.2.3
rack-mount-0.6.14
rack-test-0.5.7
rails-3.0.5
railties-3.0.5
rake-0.9.2
sqlite3-1.3.3
thor-0.14.6
treetop-1.4.9
tzinfo-0.3.28

create a new rails project

$ rails new sometestpro

gem_install

$ gem install somegem

install bundler in the gemset

$ gem install bundler
Fetching: bundler-1.0.15.gem (100%)
....
Successfully installed bundler-1.0.15

$ ls $GEM_HOME/gems
bundler-1.0.15

rvm_gem_home

$ rvm use 1.8.7
Using /Users/lakshman/.rvm/gems/ruby-1.8.7-p334

$ echo $GEM_HOME
/Users/lakshman/.rvm/gems/ruby-1.8.7-p334

$ rvm use 1.9.2
Using /Users/lakshman/.rvm/gems/ruby-1.9.2-p180

$ echo $GEM_HOME
/Users/lakshman/.rvm/gems/ruby-1.9.2-p180

set up new rvm gemset and use it

$ rvm gemset create testing
'testing' gemset created (/Users/lakshman/.rvm/gems/ruby-1.9.2-p180@testing).

$ rvm use 1.9.2@testing
Using /Users/lakshman/.rvm/gems/ruby-1.9.2-p180 with gemset testing

$ echo $GEM_HOME
/Users/lakshman/.rvm/gems/ruby-1.9.2-p180@testing