42

Problem

You want to be able to use different gems/rails version for your application after installing the latest rails version, without having to use bundle exec.

Solution

You can use the named gemsets with rvm.

More instructions are here: http://beginrescueend.com/gemsets/basics/

so you can install two gemsets for example ruby-1.9.3-p0@rails3_0_11 and another with ruby-1.9.3-p0@rails3_2_1

you could then do :

rvm gemset create rails3_0_11 rails3_2_1

rvm 1.9.3-p0@rails3_0_11
gem install rails -v 3.0.11

rvm 1.9.3-p0@rails3_2_1
gem install rails -v 3.2.1

rvm gemset use rails3_0_11
bundle install

Problem

If you have setup guard with your Rails project and you are trying to run it in an (K)Ubuntu installation you get the following message:

Could not open library 'libgtkmm-2.4.so': libgtkmm-2.4.so: cannot open shared object file: No such file or directory.

Solution

Install the missing library with the following:

sudo apt-get install libgtkmm-2.4