How to build a gem from rails source code?

Question

I want to make a gem from rails source code and install the gem.

After clone the master repository of rails, I tried as follow.

$>gem build rails.gemspec 
$>gem install rails-4.2.0.alpha.gem

It did not work. I also tried $>rake install which did not work either.

Looking forward your help!

Answer 1

There is a script in the root directory which builds from source and installs the gems. It's called install.rb. You can use it by running the following:

ruby install.rb 4.2.0.alpha

Note: At the time of writing this the arel gem needs to be built from source and installed separately before running the install script above. This is because the version constraints in rails are requiring a version of arel which has not yet been released onto rubygems.org.