Bootstrap variable overriding with LESS

Overriding variables after importing the original bootstrap.less works great for me:

@import "less/bootstrap.less";

@body-bg:     red;
@text-color:  green;
@link-color:  blue;

Compiling the above LESS source outputs properly customized Bootstrap CSS code.

Relevant info: http://lesscss.org/features/#variables-feature-lazy-loading