I'm using Sass 3.4.9, Compass 1.0.1, and Ruby 1.8.7. I don't believe I'm using Rails since when I run rails -v it says "Rails is not currently installed on this system" and instructs me on how to install it.
After upgrading Sass and Compass, the compile time is about 5 minutes. I would guess this is about an extra 2 minute increase from before. FYI, the previous build time of about 3 minutes is not unexpected since I'm working with a very large codebase. But very little has changed after I upgraded. I've looked around for answers and haven't found anything conclusive. I tried removing some @extend directives. That didn't work. What I would like is to understand what is causing the problem (i.e. especially if it's a Sass or Compass issue and what that specifically is) and what to do about it so I can return to the previous build time if not faster.
EDIT - I reverted Sass to 3.1.15 (kept Compass 1.0.1), and in fact the compile time took about 1.5 minutes.
The thread at https://github.com/sass/sass/issues/1019 does not provide any solutions or any concrete explanations on the cause.