Git HTTP error installing Compass on Rails 3.1 project

I am following the guidance provided in this Q&A to install Compass on Rails 3.1 project:

How to use compass with rails 3.1

When I run the bundle update, however, I get the following error:

Fetching https://github.com/chriseppstein/compass.git
error: The requested URL returned error: 403 while accessing https://github.com/chriseppstein/compass.git/info/refs

fatal: HT开发者_运维知识库TP request failed
Git error: command `git clone 'https://github.com/chriseppstein/compass.git' "/Users/csc/.rvm/gems/ruby-1.9.2-p290/cache/bundler/git/compass-71785749c1e54e7e5936dbddfb919ddd014100e8" --bare --no-hardlinks` in directory /Users/csc/source/wtt has failed.

Any guidance would be appreciated.

Since you're getting an HTTP error code, can you try using the git protocol?

git clone git://github.com/chriseppstein/compass.git