Gulp不再编译scss文件了

Question

我看到Gulp不再编译我的scss文件的问题了。我没有对gulpfile.js做任何改动，所以可能导致它的原因。我的代码如下：

gulp.js

var gulp = require('gulp');
var gutil = require('gulp-util');
var bower = require('bower');
var concat = require('gulp-concat');
var sass = require('gulp-sass');
var minifyCss = require('gulp-minify-css');
var rename = require('gulp-rename');
var sh = require('shelljs');

var paths = {
  sass: ['./scss/*.scss']
};

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

gulp.task('sass', function(done) {
  gulp.src('./scss/ionic.app.scss')
    .pipe(sass())
    .on('error', sass.logError)
    .pipe(gulp.dest('./www/css/'))
    .pipe(minifyCss({
      keepSpecialComments: 0
    }))
    .pipe(rename({ extname: '.min.css' }))
    .pipe(gulp.dest('./www/css/'))
    .on('end', done);
});

gulp.task('watch', function() {
  gulp.watch(paths.sass, ['sass']);
});

gulp.task('install', ['git-check'], function() {
  return bower.commands.install()
    .on('log', function(data) {
      gutil.log('bower', gutil.colors.cyan(data.id), data.message);
    });
});

gulp.task('git-check', function(done) {
  if (!sh.which('git')) {
    console.log(
      '  ' + gutil.colors.red('Git is not installed.'),
      '\n  Git, the version control system, is required to download Ionic.',
      '\n  Download git here:', gutil.colors.cyan('http://git-scm.com/downloads') + '.',
      '\n  Once git is installed, run \'' + gutil.colors.cyan('gulp install') + '\' again.'
    );
    process.exit(1);
  }
  done();
});

的package.json

{
  "name": "app-mobile",
  "version": "1.1.1",
  "description": "app-mobile: An Ionic project",
  "dependencies": {
    "gulp": "^3.5.6",
    "gulp-concat": "^2.2.0",
    "gulp-minify-css": "^0.3.0",
    "gulp-rename": "^1.2.0",
    "gulp-sass": "^2.0.4",
    "ng-tags-input": "^3.1.1"
  },
  "devDependencies": {
    "bower": "^1.3.3",
    "gulp-util": "^2.2.14",
    "jasmine-core": "^2.5.2",
    "karma": "^1.3.0",
    "karma-chrome-launcher": "^2.0.0",
    "karma-jasmine": "^1.0.2",
    "karma-phantomjs-launcher": "^1.0.2",
    "shelljs": "^0.3.0"
  },
  "cordovaPlugins": [
    "cordova-plugin-device",
    "cordova-plugin-console",
    "cordova-plugin-whitelist",
    "cordova-plugin-splashscreen",
    "cordova-plugin-statusbar",
    "ionic-plugin-keyboard"
  ],
  "cordovaPlatforms": []
}

目录结构

|-- hooks
|-- node_modules
    |-- all of those...
|-- platforms
|-- plugins
|-- scss
    |-- dingocv.scss
    |-- ionic.app.scss
|-- www
    |-- app
    |-- css
        |-- ionic.app.css
        |-- ionic.app.min.css
        |-- style.css
    |-- fonts    
    |-- img
    |-- lib

我的SCSS文件（dingocv.scss）已发布here。