Undefined Variable on rake publish?

[dallasbpeters]

wondering if anyone else has this issue:

@import "bourbon";
@import "variables"; //this needs to load first because we are overiding Foundation defaults
@import "foundation";
@import "typography";
@import "base";
@import "topbar";
@import "mediaqueries";

in "_variables.css.scss":

$black:#2d3133;

in "base.css.scss"

background: $black;

Middleman is not reporting any undefined variable, however when I rake build and then rake publish I'm getting:

/source/stylesheets/base.css.scss:8: Undefined variable: "$black". (Sass::SyntaxError)

[dallasbpeters]

Think I figured it out. "base.css.scss" should have had a physical name "_base.css.scss"