Answering my own question, in case this can help anyone else:
The only way I found solving this, is using the node-sass CLI through grunt. To achieve this, install the amazing grunt-exec task and set it to run a command with the --watch option.
An example usage (with support for several includePath directories):
exec: {
nodeSass: {
cmd: function() {
// Include path option string built from the gruntConfig.cssFiles array.
var includeFilesOption = gruntConfig.cssFiles.map(function(cssFilePath) {
return '--include-path ' + cssFilePath;
}).join(' ');
return 'node-sass app/scss/style.scss app/generated/style.css' + includeFilesOption + ' --watch';
}
}
}
You will also need to install node-sass via npm. In that case, you can simply add the following to your package.json file:
"scripts": {
"install": "npm install node-sass -g"
},