Can't get sass + compass + susy installed due to version conflict

I'm working with Sass, Compass and Susy on OSX / Terminal. But I can't get Susy to work together with Sass and Compass. What I've done:

sudo gem install sass
sass -v

Returns: Sass 3.3.0 (Maptastic Maple)

sudo gem install compass

This seems to also install sass-3.2.14.gem, then the compass-0.12.3.gem.

compass -v

returns: Compass 0.12.3 (Alnilam)

Everything until this point seems to work fine; I can create a Compass project and work with it. Then I try to install Susy:

sudo gem install susy --pre

or just

sudo gem install susy

This seems to install susy-2.0.0

Than I run:

compass create /Users/tom/Thomas/htdocs/susi4-test -r susy -u susy

And I get this error:

Gem::LoadError on line 2064 of /Library/Ruby/Site/1.8/rubygems/specification.rb: Unable to activate susy-2.0.0, because sass-3.2.14 conflicts with sass (~> 3.3.0)
Run with --trace to see the full backtrace

So there seems to be a problem with the compatibility of the different versions. What can I do to resolve this error?

Solution 1:

The dependencies are incompatible: susy 2.0.0 depends on sass ~> 3.3.0 whereas compass 0.12.3 depends on sass = 3.2.14.

The error message says the same:

Unable to activate susy-2.0.0, because sass-3.2.14 conflicts with sass (~> 3.3.0)

You can a) downgrade susy to a version that's working with sass 3.2.14 or b) upgrade compass to a version compatible with sass 3.3.x.

A compatible version is compass 1.0.0 (or later) depending on sass < 3.5, >= 3.3.13. You can install it via

gem update compass

It might be easier to use a gem manager like Bundler. It automatically resolves dependencies and installs the appropriate versions.