Why doesn't the gulp-file-include plugin work?

Question

gulp.js

Installed the gulp-file-include plugin.
gulpfile.js config:

gulp.task('fileinclude', function() {
  gulp.src(['app/index.html'])
    .pipe(fileinclude({
      prefix: '@@',
      basepath: '@file',
    }))
    .pipe(gulp.dest('./'));
});

When executed, it gives an error: Did you forget to signal async completion?
What could be the problem, how to fix it?
npm 6.4.1
gulp 4.0.0

Answer 1

There are thousands of questions with this error all over the Internet and moreover with a solution
Read the documentation https://gulpjs.com/docs/en/getting-started/async-c... before using the tool

gulp.task('fileinclude', function() {
  return gulp.src(['app/index.html'])
    .pipe(fileinclude({
      prefix: '@@',
      basepath: '@file',
    }))
    .pipe(gulp.dest('./'));
});

Answer 2

On stackover, there seems to be an analysis of this problem - here