1、task function must be specified

输入gulp -v，查看gulp是否可用

gulp工具正常的话检查代码

4.0.0版本的，“default”右边两个参数放在gulp.series()的参数中，否则会报错

修改后成功

2、 gulp.start is not a function

gulp.task('task1', gulp.series('task1-1', function (done) {
   // task 1 code here
    done();
}));
 
gulp.task('task2', gulp.series('task2-1', function (done) {
   // task 2 code here
    done();
}));
 
// Similarly Tasks 3 and 4 Code here
 
gulp.task('main', gulp.series('task1', 'task2', 'task3', 'task4', function (done) {
    done();
}));

3、The following tasks did not complete: default Did you forget to signal async completion?

 原本的gulpfile.js如下

const gulp = require('gulp')
gulp.task('default',()=>{
    // console.log('default task');
    gulp.src(['src/**/*'])
        .pipe(gulp.dest('build'))
   
})

改成如下的形式就可以了

const gulp = require('gulp')
gulp.task('default',function(done){
    // console.log('default task');
    gulp.src(['src/**/*'])
        .pipe(gulp.dest('build'))
        done()
})