gem install in depth

Question

I have installed OS X Lion, that have Xcode 3.2 deprecated.

I'm working on Rails project and have to install rmagick, which depends on ImageMagick.

Right now i'm not be able to download Xcode 4.2, because it takes 2.9GB.

I cannot also build ImageMagick from sources.

I'm having access to another mac with OS X Leopard, which has all necessary gem installed.

I can just copy them to my working Mac with OS X Lion.

But, what files do I need to copy ?

I think, that having gems to copy from ~/.rvm/gems/ruby-1.8.7-p334/gems/ is not enough, or ?

The question is:

What happens, when i run "gem install some_gem" ?

What files are copied where and what processes gets executed ?

Answer 1

You really can't copy from one OS to another, especially if there are significant versions in the dynamic libraries. In order to install gems like ImageMagick you will need a working compiler, so you'll need to download Xcode 4.1 for Lion.

When you run gem install, a number of things happen. For pure ruby Gems it's nothing complicated, basically extracting the gem into the proper gem directory, but for those with C extensions, like ImageMagick, there is a lot of configuration and compilation that must occur.

Basically you're stuck. You either need to install the compiler, or roll back to the older version of the OS.