title: Gulp watch don't overwrite files
body: <p>When I launch gulp generates me the files, but when it enters the watch mode, understands that there was a change but does not overwrite files:</p>
  
  <p>My gulp sample</p>
  
  <pre><code>var argv = require('yargs').argv;
  var gulp = require('gulp');
  var gulpif = require('gulp-if');
  var uglify = require('gulp-uglify');
  
  var dependencies = [
      'core-js/client/*.min.js',
      'zone.js/dist/zone.js',
      'reflect-metadata/Reflect.js',
      'systemjs/dist/system.src.js',
      'rxjs/**/*.js',
      '@angular/**/*.js',
      'angular2-in-memory-web-api/*.js',
  ];
  
  var modules = [
      // Example: 'iconv-lite/**/*',
  ];
  
  ........
  gulp.task("javascript", () =&gt; {
      return gulp.src([
          './bower_components/jquery/dist/jquery.min.js',
          './bower_components/bootstrap/dist/js/bootstrap.min.js',
      ])
          .pipe(gulp.dest("./build/js"))
  });
  
  gulp.task('styles', () =&gt; {
      var postcss      = require('gulp-postcss');
      var autoreset    = require('postcss-autoreset');
      var simplevars   = require('postcss-simple-vars');
      var nested       = require('postcss-nested');
      var lost         = require('lost');
      var cssnext      = require('postcss-cssnext');
      var processors = [
          simplevars(),
          nested(),
          lost(),
          cssnext(),
      ];
      return gulp.src([
              './src/css/*.css',
              './bower_components/openSans/openSans.css',
              './bower_components/components-font-awesome/css/font-awesome.min.css',
              './bower_components/bootstrap/dist/css/bootstrap.min.css',
          ])
          .pipe(postcss(processors))
          .pipe(gulp.dest('./build/css'));
  });
  
  gulp.task('ts', ['ts-app', 'ts-electron']);
  
  gulp.task('build', ['templates', 'resources', 'styles', 'ts', 'libs', 'modules', 'images', 'javascript']);
  
  gulp.task('watch', ['build'], () =&gt; {
      gulp.watch('./src/app/**/*', ['ts-app']);
      gulp.watch('./src/electron/**/*', ['ts-electron']);
      gulp.watch('./src/resources/**/*', ['resources']);
      gulp.watch('./src/css/**/*', ['styles']);
      gulp.watch('./src/templates/**/*', ['templates']);
      gulp.watch('./src/img/**/*', ['images']);
      gulp.watch('./src/js/**/*', ['javascript']);
  });
  </code></pre>
  
  <p>Platform: Win7x64
  NPM: 3.10.8
  NODE: v6.7.0
  Gulp version:</p>
  
  <pre><code>{
      "gulp": "^3.9.1",
      "gulp-if": "^2.0.1",
      "gulp-postcss": "^6.1.1",
      "gulp-pug": "^3.0.3",
      "gulp-typescript": "^2.13.6",
      "gulp-uglify": "^1.5.4",
  }
  </code></pre>
  
  <p>I also tried to manually put <code>gulp.dest("./build/", {overwrite: true})</code>(in all gulp.dest) but nothing change :/
  What can I do to better understand the problem?</p>