var gulp = require('gulp'),
    less = require('gulp-less');

// Compile Our Less
gulp.task('less', function() {
    return gulp.src('bower_components/bootstrap/less/bootstrap.less')
        .pipe(less().on('error', function(err){
            errorLog(err);
        }))
        .pipe(gulp.dest('compiled-bootstrap-css'));
});

gulp.task('default', ['less']);

function errorLog(err){
    console.log(err);
}

[16:08:01] Starting 'less'...
{ [Error: Missing closing ')' in file d:UserstroutiIdeaProject
bower_componentsbootstraplessmixins.less line no. 552]
  type: 'Parse',
  filename: 'd:\Users\trouti\IdeaProjects\PublicPortal\bower
otstrap\less\mixins.less',
  index: 17957,
  line: 552,
  callLine: NaN,
  callExtract: undefined,
  column: 8,
  extract:
   [ '    .spanX (@index) when (@index > 0) {',
     '      (~".span@{index}") { .span(@index); }',
     '      .spanX(@index - 1);' ],
  message: 'Missing closing ')' in file d:\Users\trouti\Idea
cPortal\bower_components\bootstrap\less\mixins.less line no.
  stack: undefined,
  lineNumber: 552,
  fileName: 'd:\Users\trouti\IdeaProjects\PublicPortal\bower
otstrap\less\mixins.less',
  name: 'Error',
  showStack: false,
  showProperties: true,
  plugin: 'gulp-less',
  __safety: { toString: [Function] } }