In this line: var paths = require('compass-options').paths(); the paths var get a full path, like sites/all/themes/theme_name/sass but need use de relative path like sass to "grunt watch" work. To fix this problem, I changed this line to: var paths = require('compass-options').dirs();
In this line: var paths = require('compass-options').paths(); the paths var get a full path, like sites/all/themes/theme_name/sass but need use de relative path like sass to "grunt watch" work. To fix this problem, I changed this line to: var paths = require('compass-options').dirs();