I'm not sure if there is a reason that you want to do includePaths in your gulpfile, but for bootstrap you don't have to. The bootstrap include path is already configured out of the box in /node_modules/laravel-elixir/ingredients:
elixir.extend('sass', function(src, output, options) {
options = _.extend({
outputStyle: inProduction ? 'compressed' : 'nested',
includePaths: [elixir.config.bowerDir + "/bootstrap-sass-official/assets/stylesheets"]
}, options);
return compile({
compiler: 'Sass',
pluginName: 'sass',
pluginOptions: options,
src: src,
output: output,
search: '**/*.+(sass|scss)'
});
});
So all you should have to do is, in your gulpfile:
elixir(function(mix) {
mix.sass("style.scss");
});
And then in your style.scss:
@import "bootstrap";
I think you have to set your .bowerrc file to:
{
"directory": "vendor/bower_components"
}
but it looks like you have already done that.